Make sure you have a copy of all the mails and the documents exchanged between you and the two banks. In addition to this, keep all the documents submitted and received from the III tier grievance redressal system of IDBI. Do visit the website of IDBI and HDFC to find out if they have any other mechanism to solve grievances of the consumer. Although you have filed a complaint before the grievance redressal system of IDBI, now try to identify the highest possible authority for grievance redressal there and file your complaint again before it. This is important as it will help you in your next step. If the Banks are unable to solve your problem after your complain to highest redressal body then you can approach the Banking Ombudsman created by the RBI to regulate the Banks and protect the interest of the consumers under the Banking Ombudsman Scheme, 2006. You can file a complaint on this link- https://secweb.rbi.org.in/BO/precompltindex.htm
. The complaint can be filed within one year from the date on which you received a response from the Bank’s officials against your complaint. The Banking Ombudsman will require you to submit all the relevant documents regarding the issue. Clause 8 of the Banking Ombudsman Scheme, 2006 provides the grounds on which a complaint can be filed before the Ombudsman.
Your issue can be covered under some of the grounds provided in the list and therefore you can file it before banking Ombudsman. Further the Banking Ombudsman will take up the issue only when it is satisfied that you have approached the correct authorities at the Bank to solve the problem before approaching the Ombudsman. Therefore preserve all the documents exchanged and received from the Banks and the grievance redressal team of the Banks. The Banking Ombudsman will consider all the documents placed before it by you and the Bank and try to act as a mediator and help you and the Banks to settle the dispute and arrive to an agreement. You also have the option to lodge a complaint with Consumer Forum under the Consumer Protection Act, 1986. Approach the correct jurisdiction and your lawyer will guide you in the most efficient manner. Also, in Consumer Forum, you can choose to represent yourself. You can also seek damages if you wish to.
There have been multiple complaints against the banks who harass customers for no reason. Even the Supreme Court has taken cognizance of the same on multiple instances. In Ms. Jyoti Khurana v. Kotak Mahindra Bank 
, the complainant was harassed for no reason or fault of her and when she approached the Consumer Forum, damages worth Rs. 1,00,000 were awarded to her. 
Refer to https://www.rbi.org.in/Scripts/FAQView.aspx?Id=24
Last seen on 21-05-2016
Researcher - Vidit Mehra