MTN Contract Cancellation

I have email MTN at *** on the 3de of December 2020 to buy out my current contract due to me immigrating to the UK end of January 2021. MTN has responded to my request and provided me with banking details. ABSA did not accept the details provided via internet banking and red flagged the account. I have since emailed *** and have not received any response or feedback from MTN at all?