Dear Munender,
At the outset, let me clarify that this site is designed by a group of senior Banking Professionals to assist Bank Customers at large to provide guidance for resolution of any complain/query/grievance in respect of financial services. This site does not belong to any Bank or a regulator, which may please be noted.
As per RBI guidelines banks can recover late payment charges only if the credit card account remains 'past due' for more than three days. That is, if you have paid the amount on the due date mentioned on the credit card statement there is no case for recovery of late payment charges by your bank.
You have stated that you deposited a cheque well in time to ensure payment of your dues by the appointed date that is 7th April 2016. But the bank has not been able to account for the cheque. If the bank has acknowledged that your cheque deposited in the drop box was lost, the accountability rests with them. If your account had sufficient balance to honour the cheque had it been presented would entitle you to seek reversal of the late payment charges debited by your bank.
As several issues are involved which need to be looked into for ascertaining the facts, I suggest you to take up with the Nodal Officer of your bank seeking redressal. Ensure that complete details like due date for payment of dues, actual date of deposit of the cheque towards its payment, and also copies of mails exchanged with Customer Service Department of the bank are provided to the Nodal Officer. Contact details of Nodal Officer of the bank can be found on the bank's website.
Give 15 days time for the Nodal Officer to respond. In case you do not receive any response or the response does not satisfy you, the matter may be escalated to the Banking Ombudsman for resolution. While writing to the BO, please provide complete details and also enclose the communications exchanged with the bank.
For address of the Office of the Banking Ombudsman, Area of Operation (jurisdiction) and the procedure for lodging complaint, you may access the website https://bankingombudsman.rbi.org.in/
Regards
J R Mohandas