4 months of pure customer service hell

On April this year, I went to MTN the Glen, to upgrade my two daughters cellphones. I was assisted by Tshidi who assured me that both phones were blocked once the package data/airtime was done and the phones would be on pay as you go. In May I received a bill of R4000. When I contacted Tshidi I was told that from her side it was blocked but MTN head office hadn't processed the request. To cut a long story short, since May, I have being dealing with Cosmo Net regional manager Vaughn, George another director and several MTN customer care call centre people. No one has being able to fix this problem and everyone is blaming each other, and I the customer am stuck in the middle with 2 daughters studying away from home, and cellphones that have being suspended. I have begged, pleaded, cried, screamed, threatened and yet NO ONE seems to give a damn! How is it even possible that a company as big as MTN can't get their **** together!!! It's their mistake, but yet no one wants to take ownership of it and no one wants to fix it!!!!!!