3RD PARTY DEBIT ORDER NOT ALLOWED?

My cell phone account is paid for by my business as I use it for work, cell phone is in my name. For the last 18 years this has been the case. MTN apparently recently changed their systems, and I was told when I upgraded that I was required to provide my banking details and would be able to update the banking details to my business bank account once the upgrade has been done. So I upgraded based on this information. I have now been trying to change the debit order banking account for over a month and no one seems to know what to do or willing to assist. I have provided a letter from the directors of the company with copies of their ID's, company registration and proof of banking account and still no one at MTN is willing to assist. Surely a company cant be so backward that their systems do not allow 3rd party debit orders? Its got nothing to do with the POPI act (which was one excuse I got) who at MTN can assist me as I am tired of speaking to call centre agents that don't know what they are doing and unwilling to assist a customer!