Poor service from ABSA

I received a letter in August 2019 from a Customer Service representative confirming that I had no account with ABSA before the opening of my savings account. Today the company who needed the letter phoned the representative and then he said that he cannot confirm that I had no previous account because after 5 years the older accounts is being wiped and now the company refuse to pay me the money they owe me. What the representative told the company is a lot of bull because there is a personnel matter between myself and the representative and that is why he changed his story.