Poor customer service

A Telkom agent calls and offer me an upgrade on my phone which I declined. I took an offer on my data SIM instead and checked with him that we are talking about the correct number and he confirms. My mobile phone then cannot make calls and I find out he changed this to a data contact. The call center lady I am dealing with says the system shows I did the upgrade in the shop and not online. She refuse to put me through to her supervisor and puts down the phone when I ask for her name. At the Telkom shop I am advised that they cannot help as I did the deal with a call center. Another person at the call center says they will see what they can do in the next 72 hours and says that my legal cooldown period is valid but if I exercise that they will cancel my mobile contract and it will be pay as you go. I guess after been with them for more that eight years it is time to move on.