BAD SERVICE FROM MTN

In 2003 my dad took out a contract at MTN for myself and my niece. After he passed away in 2007 my mom continue with the account and added another contract. My mother (72) lives 2 hours form the nearest 'big' town, which is Jeffery's Bay. In January 2021 she made a payment at MNT, Zevenwacht Mall, Kuilsrivier. Our phones was disconnected because it showed that the account was in arrears. She then took proof of payment to MTN Zevenwacht Mall. We discussed the matter with the manager Stephen. He mailed me saying that he forwarded the proof payment to their accounts department. When I went to pay at the end of September 2021 I found out that the account was R3000.00 in arrears. I then asked to spoke to the manager again. They told me he was on leave until the 18 of October 2021. I then send him a mail enquiring why the account has not be sorted out yet. After the 18th I went back to the store and spoke to him. He then told me he is still busy going through is e-mails and will come back to me. Saturday the 30th of October 2021 I went back to the store, because he did not contact me. One of the other employees took my number said he is busy and he will give me a call. I am still waiting for him to come back to me. We are due for an upgrade but cannot because the account is in "arrears".