MTN Worst customer service ever

Worst service ever. Mtn keeps sending me notification that I am due for upgrade. On enquiring I am told no sorry.only end of May 2023. Since 26 Jan I am not able to receive or make calls also cannot call 135. I keep getting pop up's to say I am not signed into the network. I have escalated this matter so many times but not a single effort to resolve this. I will not be upgrading in May, I will take my business elsewhere