Cancellation of Cellphone Contract

On the 7th of August I phoned MTN to advise them that I wished to cancel my contract which is coming to an end on the 7th of September. When making this phone call I had to wait on the phone for approximately 30 minutes. Fortunately, it's a toll free number so apart from wasting my time no monetary expenses were incurred. Over the weekend I sent an email to Customer Care ********** requesting confirmation of this earlier cancellation and asking that they please ensure that the debit/stop order will also be cancelled. I then receive a reply from MTN advising me to PHONE Customer Care and discuss with them. Why should I have to phone them when I've sent an email, which they advertise as a means of contacting them, giving details of my query? I DO NOT want to have to phone and sit around for another 30 minutes listening to some insane repetitious bit of canned music. Why is it that the MTN representative who received my email couldn't simply look up my record on the computer and ensure everything was in order regarding the cancellation which had already been done, confirmed at the same time that the debit/stop order had been stopped, or would be, and then advised me accordingly. Instead of telling me to phone the very Department that my email was sent to. Thank you.