Telkom debit order cancelletion

I would prefer to give Telkom zero rating. I cancelled my mobile contract in December 2020, received an official email with reference number stating that my contract has been cancelled. All is well so far. My last debit order went off in January 2021 for December 2020. On contacting Telkom, (2 branches at Cresta), calling their finance department, cancellations etc I receive one repetative line everytime: I DON'T KNOW HOW TO CANCEL A DEBIT ORDER from consultants at Telkom. I eventually got hold of someone who said I must send an email to the cancellations department, to no avail, as every month I have to have the debit order disputed and refunded to me. If anyone can assist in helping me to cancel the Telkom debit order which they set in place. I will be very happy.