An unathorized 3000 debit order

I had a cellphone contract with MTN which was taken in store. Which means they have all my paper work and signature. That contract ended and was cancelled in 2023 November.

31 of August 2024 debit order of R3038 goes off on my account from MTN. Because it was the weekend I waited till today the 2nd sept 2024. I called my bank to reverse it and I was told since it’s mandated they can’t reverse or stop it. I did not authorise that debit. So I called MTN to reverse it and they refused. Apparently I took out an iPhone 15 online and it was delivered to an address in Cape Town.

The constant I spoke to wasn’t helpful she just said I should get an affidavit to say I don’t know the number that they claim is mine. She did not have the answers to my questions. Who signed for this phone? How did they verify it’s actually the right person opening the contract. MTN please bring back my money.