Bad service-no communication

No call back-no email-no communication. I have a contract with MTN, I’ve tried multiple times to get them to call me to upgrade my contact and no response, no call back. I am a loyal customer but for them not to even communicate back to me is pathetic. STOP USING ITALK to call me because they are absolutely pathetic and always trying to sell me something which never works out- do your job. I am absolutely furious because I have been back on forth on email with mtn and they always say they are going to call but don’t ever end up assisting me. I’m trying to upgrade my contract and give them business and support but they are absolutely not interested in that.