Hi,
could you pls let me know whether this sentence is correct grammatically or not?
*if i haven't received any reply till today, i will return the shpt to the customs.*
in advance thank you for your help
No, it's not correct.
Two capital letters are missing. (Can you see where they should be?)
Abbreviations should not be used in careful English, and the abbreviation 'shpt' is not even commonly used in less careful English.
When you write this, do you not know whether you have received a reply 'today'? Possibly you should say 'by the end of business today'. 'By' is better than 'till'.
Clive