Is this a case of neligence and do I have a case?

I worked for a company 20 years ago that had purchased some sort of cash balance stock plan for their employees. When I had quit I called them and asked if there was money for me and they said had no records of it. 20yrs later I was watching a infomercial and said there is money due to some people and I thought of this so I called the company again and they said they would check on it and later to find out there was. The funny thing is the bank that had been holding this money is the same bank I recently worked at for 5 YRS and when I had left the bank I was never informed nor when I worked their. So when told the value of the funds I feel if told 20yrs ago the value would have been much higher when the stock market was better I feel that the company and the bank I worked for was negligent