PHOENIX -- Paul and Christine Dickey have a certificate of deposit worth $400,000, but they have not been able to collect the cash.

The Casa Grande couple has spent a year trying figure out which bank owes them the money.

Paul's father bought the $10,000 CD in 1980 from First National Bank of Arizona branch in Benson, Ariz. Since then, the bank has changed hands three times.

"I hope we get to the bottom of who owns the bank that this is written on, “ Christine Dickey said.

In 1981, the bank changed its name to First Interstate Bank.

In 1996, Wells Fargo bought the bank.

In 1997, the National Bank of Arizona took over and still owns the branch today.

Tuesday, a representative said he was unable to find any record for any certificate of deposit for Paul Dickey.

"Pure frustration,” is how Dickey describes his interactions with employees at the bank.

“Nobody wants to take responsibility for this,” Christine said.

The Dickeys have hired a lawyer to help, but he told CBS 5 News he has no idea which bank is responsible for cashing the CD.

The Dickeys discovered the CD last fall while searching through old documents.

"This thing appeared in my hands and I looked at it and I gasped,” Paul said. "I'd completely forgotten it."

“It was purchased by husband's father…who was dying at the time. It was sort of payment to my husband for taking caring of him,” Christine said.

The couple said if they ever figure out who owes them $400,000, they plan to donate some of the money to charity and save the rest for a rainy day.

"I see not-too-good of times facing us right now, and it would smooth over a lot for our family,” Dickey said.