MTN refusing to close a paid up account

I have been struggling to get a paid up letter from MTN. I've been in email correspondence with the *** email since December 2021 with no luck. On 7 January 2022 I made a payment arrangement with Lesiba and paid into into the ABSA account he gave on 22 February 2022 and 1 March 2022, completing the entire outstanding amount he had quoted. I also explained that internet banking only allows a cellphone number and not the ref number, which is how it has been set up by MTN. On 14 March I received an email from the *** account specifically stating that it would take two weeks to correctly allocate the funds to the reference number. I have given the address POPs and all the account details numerous times and have asked if I need to re-submit anything else. I have received no answer. The last email I received from *** was on 9 April 2022 from Khenani.

I have also included *** and *** (who tried to help but received no assistance from MTN to close the account) on emails dated 18 March 2022 and 1, 8, 22 April 2022 with POPs and correspondence history.

I simply need a closed account letter from MTN.