Contracts under false information

I was upgraded from 10gb to 20GB and was advised that the amount is not going to change , on the next invoice i see i have been charged an amount for Device obligation fee, which wasn't agreed with me, before i upgraded i confirmed 3 times if the amount will change and was advised "no, you will continue paying the same amount as you were" in essence Telkom made me agree to a contract under false information. Im not surprised telkom is the pits ,cant wait for finish my contract and leave them. If you are thinking of joining telkom i would advise you to think otherwise, Telkom has too many issues when it comes to billing. Im still waiting for a response from them