FDIC doesn't have anything to do with this whatsoever as well.
The FDIC is a bank regulator, and is the primary banking regulator for many banks. Other bank regulatory agencies are the Office of Thrift Supervision (OTS), the Office of the Comptroller of the Currency (OCC), and the Federal Reserve. The NCUA regulates credit unions. There are also state banking regulators, but if I were starting out on this, I would start with the FDIC. (There is a long list of ways to try to work which agency is the primary regulator at the bottom of this page.)
From the FDIC's website, which explains how for consumers to get help with a banking problem:
If the consumer has a complaint against a financial institution, the first step is to contact an officer of the institution and attempt to resolve the complaint directly. Financial institutions value their customers and most will be helpful. If the consumer is unable to resolve the complaint directly, the financial institution's regulatory agency may be contacted for assistance.
The agency will usually acknowledge receipt of a complaint letter within a few days. If the letter is referred to another agency, the consumer will be advised of this fact. When the appropriate agency investigates the complaint the financial institution may be given a copy of the complaint letter.
The complaint should be submitted in writing and should include the following:
- Complainant's name, address, telephone number;
- The institution's name and address;
- Type of account involved in the complaint--checking, savings, or loan--and account numbers, if applicable;
- Description of the complaint, including specific dates and the institution's actions (copies of pertinent information or correspondence are also helpful);
- Date of contact and the names of individuals contacted at the institution with their responses;
- Complainant's signature and the date the complaint is being submitted to the regulatory agency.
The regulatory agencies will be able to help resolve the complaint if the financial institution has violated a banking law or regulation. They may not be able to help where the consumer is not satisfied with an institutions's policy or practices, even though no law or regulation was violated. Additionally, the regulatory agencies do not resolve factual or most contractual disputes. (From the FDIC website, http://www.fdic.gov/consumers/consumer/rights/index.html)
(My emphasis added in the first and final paragraph.)
I believe that it is a legal obligation for the bank to honor valid instruments drawn on that bank's accounts that have sufficient funds to pay them and that have not had a stop placed on them, but that's just my commonsense belief.
The regulators will know for certain if this is indeed a legal or regulatory obligation, and if it is, they will make the bank eventually comply.