MTN POOR SERVICE

I'm an MTN prepaid client. My number is administrated by Afrihost, with whom I have my fibre. My data is supp**** by Afrihost and my prepaid airtime supp**** by MTN. Airtime is therefor MTN's responsibility. I've had no connectivity since last week Wednesday... I'm unable to make calls or receive calls, but my data works fine. Feedback from MTN : reset SIM on HLR and Subscriber is active on LTE. My line then works for 10 minutes if I'm lucky. When someone calls me, a message is displayed on their device as follows - This number is not on the network. I've emailed my complaint through numerous times BUT MTN is yet to fix the issue. So fed up of sh*t service. I can't run my business, my clients aren't able liaise with me. MTN is a sh*t show!