Turkcell Blocked My Postpaid Line Automatic Payment Setup With Confusing Error

I changed my Turkcell line to a postpaid line, and when I tried to set up an automatic payment, I received a warning that an existing automatic payment order was already in place. I contacted the bank that appeared to be handling the payment, both by phone and in person at a branch, but they confirmed that no such order existed. For the past three days, I have been speaking with Turkcell customer representatives, but each person directs me to someone else without providing any solution. As a result, I cannot set up my billing date and payment. Either someone mistakenly set up a payment under my number, or there’s a system error. I expect this confusing issue to be resolved promptly.