So difficult to cancel a MTN contract

My Daughters contract ended in June 2020. we sent an email to confirm cancellation so that MTN would not debit her account on the 8 june 2020 to *** for confirmation of cancellation of account no A***.

However, we got a reply on the 10 July after the amount was debited from her account for july from the retentions dept stating her account was put on a new system and if she could please call them to cancel.

She does not have the sim card anymore as it was lost and she does not have airtime to contact them.. We have tried to not only email them but we also tried to go into a walk in MTN center where the consultant said that we had to call the retentions dept. Then she received a call from the retentions dept asking if she wants to upgrade she said no but she would like to cancel her contract.. the consultant informed her she had to contact cancellations dept she asked if she could be trasfered the consultant said no she can not transfer.

Please could someone from cancellations call her so that it can be resolved. or an email address so that we can resolve this.

T