Debit order

Good day I received text messages end of October saying I must pay my account since well MTN couldn't debit I don't know why. I ignored those messages but they kept on coming in till I paid then I received a thank you sms and a proof of payment from MTN surprisingly on the 3rd of November MTN has debited which means now I have paid double the amounts R651.25 and MTN debited R651.25.. Till today I haven't received my refund as they said they would instead they debited again.

Phone number in question: *** ID no: *** Contact number: *** Email: *** Name: Sibusiso Sekatane