Disgusting service!!!

I purchased a new phone in the beginning of December from telkom canal walk on a contract. My contract was nearly up for renewal and the gentleman Samir that worked there explained that there would be an outstanding amount I would either need to pay up front or pay over every month. I agreed to pay the monthly fee and take the new phone. On the 31 of December telkom tried to debit me of R5100 which obviously bounced. I quickly spoke to the same gentleman Samir who helped me and said that it was he's mistake and would have it sorted out. He told me to ask my bank to reverse it and my monthly fee would be R2100 which I agreed and was aware of. I have been deligently paying the amount Before the date of the 5th of the month. I have been harrased by telkom instanting I haven't been paying and must pay this R5100 upfront first. This was NOT part of the agreement and I have contacted Samir numerous times as well as telkom to please sort my account out. They have switched my account off due to a MISTAKE THEIR Employee made. It is disgusting that nothing has been done about it and again being a loyal client I am unable to use my phone. I still have not received a call back to help sort out this matter and after trying to contact the same gentleman I have been getting no response. When does an EMPLOYEE TAKE RESPONSIBILITY FOR THE MISTAKE THEY MADE!!! THIS IS EXTREMELY FRUSTRATING. After insisting I must ignore the messages sent and being harrased for money I DID NOT AGREE UPON. This will be the last time I ever use telkom and you will loose a loyal client who has used telkom for many years now. I spend over R2000 a month and this is how your clients get treated!!!