Incompetence to deal with correct information

After been working overseas for 7 years and after much consideration I signed up at Menlyn Shopping centre for a Telkom LTE mobile WiFi for R119 per month as advertised in their sales booklet in December 2014. I asked the salesperson if I find this to be too little whether I can change to the R159 option. He confirmed that it will be no problem and I can do it after 6 months. When I went to the Telkom shop at the end of August 2015 I requested to change the R119 to R159 option. The sales lady was first not sure but after communication with another person they only informed me that this will be valid for another twenty four months and the change will be effective from 1 October 2015. I was happy with that. However when I received the electronic account today it seems as if I have to pay R840 \migration fees"and another extra fee that was never even brought under my attention or mentioned to me at all - wow what a surprise! If it was communicated with me I would not have taken up the option and I do not want this change at all. There is no official site for complaints to Telkom and they just seem to ignore all my efforts to solve the problem by delaying answers."""