Contract Buyout is a Contract ***** UP!!

My grandmother was contacted last year november by the friendliest of friendly telesales person, asking why she doesnt join Cell C? she has been a loyal customer of MTN since its launch in SA, so why would she? after a lot of small talk and back and forth, The sales consultant told her that they (cell c) would buy out her MTN contract. She just had to get the early cancellation letter, and they would do the rest. BULL. I got everything for her. Today, 22 feb. she has had to pay MTN and Cell c for the past 3 months! both are blaming the other And no one is helping!! Trying to call Cell c, is useless , its like talking to the wall!!! no help from cell c, no help from mtn. I wonder whats going to happen if I cancel both, and then lodging a claim for hundreds of thousands for emotional distress after they blacklist me...