Unauthorised debit orders

I have a cheque account with Absa bank which continues to be *******ly debited by The Big Five network. This month, it was debited twice. Whenever I ask Absa to block the company from debiting my account, I'm told that they have no involvement in an agreement that involves a customer and a service supplier, which makes no sense because I have no agreement with this company, but I must pay Absa R25.00 every time I reverse the ******* debit orders. I am so tired of dealing with this matter. I have had such a bad experience with Absa over this matter.