MTN quick to sell a item impossible to cancel

We were given sub standard phones when we took a special on a tele-marketing sale. We returned the phones unused brand new to MTN in Boksburg.They told me to call MTN and give them the cancellation reference number and they would cancel the transaction via telephone. We called MTN and was bounced around for more than an hour and no one could assist us .To ad insult to injuries the person at the call center dropped the call when we got frustrated by their inablity to understand or assist with a simple request. MTN is by far the worst service provider