MTN disappointing customer care

Upgraded contract in Oct 2022. Since 1 Dec 2022 struggling. Data blocked. Grey listed. Barred, can't even buy data!!!. Then suddenly on the 12th it was "fixed". Now today airtime and data blocked. Grey listed. Barred, can't buy data or airtime. Numerous emails to *****line as well as customer care. No feedback. Tried to phone 136 and 135 with no luck. " we are experiencing high volumes........" I've been a loyal customer for almost 30 years!! Very disappointed. If I knew what I knew now when I upgraded, I would have cancelled my contract with them.