Cant cancel contract

Absolutely worst customer service ever. I have being trying to cancel my contract for 6 months now. You can't cancel in store and you have to wait 45mins to get through to the 'retentions' department that's if the call doesn't cut after 20mins of being on hold. Once you get through they give you a cancelation fee to pay and you MUST then call back! The agent told me if I send an email its unlikely to be actioned so he "recommends calling back" because they are "just so busy". Really MTN? Surely such a large company should have better systems in place with all the technology available -4IR anyone?