NO answer on 808

I have not been receiving any sms's for the past 3 weeks - everything else is working. I tried numerous times to get through to MTN 808 and 1555 - every time i phoned i held on for over 20 minutes - after getting through someone told me to switch off my phone and take out my sim as the system does not show any error on their side - i did so - but it was still not working - then after calling again and being put on hold again for over 30 minutes the guy said he'll log a fault with a technician it will take up to 7 days - it is now 8 days later and NO ONE has phoned me as yet!!!!! I called this morning to follow up and as of this moment i have been holding on for an HOUR and 22 minutes for someone to answer. I want to cancel my contract now and take out another deal somewhere else but HOW the hell will i be able to cancel if their technical department is so pathetic how long will i have to wait to cancel?? I am paying for a service and i'm not receiving anything back for what i'm paying not even SMS'S!!