There are two sentences here. The first one seems to be all right. But that sentence sounds like a creditor asking a customer to pay a bill. The second sentence sounds like the customer explaining why the payment is being made late. So the two sentences don't quite make sense--they seem to be written by two different people.
The second sentence is a run-on sentence as well. It should read something like the following. This is due to the late charge arising because we couldn't decide who should send the document. Finally we sent it, but as a result of our discussion, it was late.