MTN Bad Service

One of the call centre's that sells MTN products sold me a LTE router but **** about the speed, when I called MTN about this they said I had to take it up with that call centre then transferred me. The call centre listened to the call and found that the agent did misinform me on the call and they said they would cancel everything on their side and get a courier to collect the router. After all that MTN decides to bill me for this canceled contract and have now gone as far as listing me on ITC for this. I have logged so many incidents since 2022 to date no response no follow-up nothing. Even today I thought I should try my luck again but nothing has changed it's the usual transfer around. I don't know what to do now to have this matter resolved...