Please ensure that you do not have any other direct or indirect liability with the Bank.
When you do not have any liability whatsoever with the bank, it is their bounden duty to release all the security documents including the title deeds deposited with them for creating a mortgage.
Write with full details to the head office of the bank, preferably by Registered Post A/D (not by courier) and preserve the acknowledgement. Give a reminder likewise after one week from receipt of acknowledgement.
Still no response from Bank or resolving the issue ie. release of title deeds to you, file a complaint against the bank before the Banking Ombudsman who shall issue notice to bank and resolve the issue. For more details as to how to file complaint, go the website with the help of following link: