fradulent contract upgrades and billing for more than contract signed

I took out a contract with Telkom in October for free me 1 gig. Everything was ok until we got to June and my contract was upgraded to a free me 2 gig without my consent, this meant that my bill increased as well. I called Telkom after receiving the June invoice and was told that I must go to the store. I went to the store and there I was told they cant do anything they can only log a call for me. I was told that it would take 36 hours to resolve the matter. Almost 2 months later and I am still calling and following up on the call and each time I call I get told to call back in a few days as they are still investigating, I am in the meantime paying for the higher package which I did not authorize. Today I called again and I am told someone just closed the call but did not put any feedback as to how my contract ended up being upgraded without my consent. On top of this my contract has now been extended by about 6 months.