Cell C Are A Bunch Of *****!

So I had agreed to a cell c upgrade on my sim only contract, in order to get a new router. When an agent pitch it to me, it sounded like a great deal. I then went on an asked the agent what the catch is and he told me that there's no catch. Afterwards I asked him if there will be any additional charge on my bill. He very proudly stated that there will be no additional charge on my bill. When he told me that, I immediately told him that I accept the offer. But before he could complete the sale,he read the terms and conditions to me, which I understood. However in the terms and conditions, I never heard anything about any additional charges with regards to the upgrade. On the 14th March 2016, I had received two statements from cell c. The first one showed that I owe R0.00. Then came the second statement shortly after where it showed that I owe a lot more than what I agreed to when I initially took the contract out and this is because of the the new router I had received. On the same day, I called cell c's call centre to find out what's going on. I received a case no: *** and was told they will listen to the recording and get back to me. Till today I haven't received a call.