Upgrade turns into a double contract

My Telkommobile contract expired in October and I did not renew immediately. In December I was contacted by a call centre to see if I want to upgrade. I agreed to the SmartPlan 100 deal for iPhone 6s. I was told the cost would be around R700 per month for the contract. When I opened my bill in December I saw that the old account was never cancelled and the new contract was now R1200. My bill is now R1700 in total, in stead of R700.<br> <br> I logged a query with the call centre on the 4th of January 2016. 3 Weeks later I have not received any feedback. I've followed up at least 4 times now and everytime I get told that responsible person will call me that same day. They never do! The last time I asked to be put through to a supervisor. The agent said that the supervisor is busy but will contact me as soon as she is done on the other call. It is now 4 days later and the supervisor has not yet called me back!!<br> <br> I've tried to be patient, especially as I always had good service from Telkom Mobile, but this time it looks like I'm going to be one of the statistics of bad service!!!