Mtn cancellations

I purchased a phone contract with Mtn Direct. I was told I have a 7 day cooling off period. I exercised this cooling off option as the LG phone was poor spec and returned the device to Mtn service store Pavilion. After countless calls I was told mtn cannot assist on my account as I did my purchase through Mtn Direct(mtn outsources their telephonic sales through a 3rd part call Centre) Finally someone does my cancelation (Alice van Der merwe) but now charge me R21k (twenty one thousand) and further R1.7k.

I am without a phone or contract yet I am charged such a huge amount. No one calls or assists from. Mtns side. What shambles.