Thank you for your answer. I tried to be as clear as I could ,sorry. Let me try again please.

The delay in the receiving the papers is what we really experience in our business with the partners . That's the matter of fact and it often causes us inconvenience . In my letter I tried to explain the situation to our business partners, partly also to express annoyance or so, and to prompt them to do something about it . What would we like is that they wait with dispatching their truck until we send them a confirmation that we have received the papers related to the delivery. Having the papers before the truck has left for our destination enable us to (if there is a need for that ) make correction as to the type , quantity or some other specification of the goods to be delivered. 

I thought that the sentence " Whenever you send us your goods we receive your documents related to the delivery after the truck has already set off." clearly states all that, and I was looking for some rephrasing which would be more emphatic. The rephrased sentences were intended to put (if only slight ) emphasis on the difficulties the delay cause us, and to accentuate the fact that we actually HAVE experienced inconvenience ON SEVERAL OCCASIONS. The text following this sentence would additionaly clear my point : "...The solving of this problem would save us money and future inconvenience so we hope you will...etc).

 Please let me try with inserting some explanation in the sentences which I hope will make clearer what I intend to say, and help you help me . 

1.a) Whenever ( = ever since we started our business till now ) you've sent us your goods, we have received your documents related to the delivery when the truck has already set off ( for our destination) .

2.a)  Whenever ( in your earlier deliveries) you sent us your goods we received your documents related to the delivery after the truck had already set off.

And the same explanations apply for the sentences  1.b) and  2.b) which are modified alternatives of 1a) and 2.a) respectively , with  "would receive" ( "would" for past habits or regular actions) instead of "we have received" and "we received".

  Also, what if i put the verb in "..when the truck had already set off" in the simple past instead of the past perfect tense in the sentences under 2) ?

I really really hope that my sentences are not a total misuse of tenses and the english language. 

I also hope it don't give you a headache 

Best regards

In the future, whenever you send us goods, please contact us to verify that we have received the documents related to the order before you dispatch the delivery truck from your location. This will save us many headaches in invoice processing, and greatly improve operations.  

Sorry I did not understand your question. Here are some comments on the verb tenses in your sentences

1a) Whenever you've sent us your goods, we have received your documents related to the delivery when the truck has already set off .

 you've sent: You have sent is present perfect.  It is used for an action in the past that is not finally complete yet. 

 we have received: present perfect. It is OK to combine present perfect tenses in one sentence.

You have sent us goods, and we have received the documents.  (and we expect this pattern to continue in the present and future)

 when the truck has already set off .  (present perfect).  Herein lies the problem. The time sequence of the events is difficult to understand. If you change "when" to "before or after", then it is a little bit clearer, because "before" and "after" are more explicit in comparing time sequences.

 Whenever you've sent us your goods, we have received your documents related to the delivery after the truck has already set off .

 Whenever you've sent us your goods, we have received your documents related to the delivery before the truck has already set off .

Whenever you've sent us your goods, we would receive your documents

This sequence of tenses is not grammatically correct. "would receive" is future relative to the time context. But  with present perfect tense, the time context is not specific enough. The simple past is required, to establish a time reference point in the past. The correct form is -- > simple past / modal relative future

Whenever you sent us your goods, we would receive the documents  

2a). Whenever you sent us your goods we received your documents related to the delivery after the truck had already set off.

 Simple past is fine for the first 2 clauses.

Whenever you sent us your goods we received your documents

The problem comes with the past perfect in the last clause. This means an action completed at a time reference in the past, but there is no such time reference in the sentence. It can be fixed by adding a time reference, either one time, or an adverb making a specific time series.  Also, "before" or "after" is needed to establish the sequence of events.

Last Tuesday, when you sent us your goods, we received the documents after the truck had been dispatched. (once, specific time; note that it is better to use the passive to relate the truck to "you". Active voice is better, still)

Last Tuesday, when you sent us your goods, we received the documents after you had dispatched the truck. 

Every time that you sent us goods, we received the documents after the truck had been dispatched. (all the time)

In the past, more than 50 percent of the time that you sent us goods, we received the documents after the truck had been dispatched.   

You can also use present tense to show a habitual pattern of activities:

Sometimes when you send us goods, we receive the documents after the truck has been dispatched.

When you send us goods, we always receive the documents after the truck has been dispatched.

Note the present perfect in the last clause to show that this action was already started before the time of "receiving the documents". This sequence - present / present / present perfect compares to past / past / past perfect pattern earlier.

2b) Whenever you sent us your goods we would receive your documents related to the delivery when the truck had already set off.

See above comments.