Poor Service & Extensive waiting periods!!!

I've got 3 contracts with MTN and one has expired on the 29th of August 2022 and according to emails with MTN you have to call their call center to cancel/convert to prepaid. After holding for 20min the call was just ended. So I recalled the call center, so after 10min of holding for a operator, my call was returned from MTN. The call quality was horrible, but never the less I've explained to the operator what I want to happen and we went through the security checks and he said I must hold again. Then after a few minutes of holding the call ended. I've never received an conformation that the number has been changed to prepaid. So today I've decided to phone them again and after 18min holding the line the operator who answered the phone said she is going to transfer me to someone who can assist... Next moment it just said that the voice mail is full and your call will be ended.... The level of service that I've received is beyond POOR!!!!!!!!