MTN SUPERSONIC worst service ever!!

Service received from MTN Supersonic is BAD!! And we only just started, if things are going to be like this at installation stage, then I'm afraid to find to ask what their after sales service is like. Wondering now if this was a good choice or the worst mistake ever. We've received the router and things have been setup, but we still have no internet access. Calling their help desk yields no results, we have been calling several times a day and all we hear is that they going to escalate it. But no response from anybody. Can one still cancel at this stage? Hopefully someone will see this and come back to us.