MTN is the worst service provider

Last week Friday I got a call from Mobile Plus telling me that they are MTN. The man on the phone told me that MTN wants to give me FREE data because of the problems I have been experiencing with my data ( even though I pay every month I am unable to use my 2GB). As a customer who was already suspicious of the call I continued to ask him if it was of no charge and he confirmed multiple times! Towards the end of the call the man mumbled T's and C's and said I would he receiving FREE data at the end of the month. I then received an SMS from Mobile Plus saying my order has been processed. At this point I realised MTN did not call me and it was another company who may I add had access to ALL my personal details including my ID number and account information. At this point I was furious and drove straight to the MTN at Alberton City where I got my contract. I spoke to a lady and explained what had just happened and all she managed to tell me was that I was getting extra data. At this point I was still worried and decided to go back the next day. Another man helped me and looked on the system and informed me my contract had been migrated and I am on the gold package ( I DID NOT CONSENT TO THIS) I then explained to him that I did not authorize this and asked him to please reverse the process or help me somehow as I really cannot afford this. He then rudely told me that there is NOTHING he can do and that I must sort it out with mobile plus. He also told me if I try to cancel it my credit score would be effecfed !I left feeling completely hopeless and betrayed my by service provider who not only does nothing to help me but also gives out my information. I then proceeded to call Mobile plus and only by the fourth time were they able to help me reverse the process BUT they said they would charge me a Prorata fee for downgrading! How is that fair if I never even consented to being upgraded in the first place ! Now I await a hefty bill at the end of the month with no assistance. I am extremely disappointed in MTN and will never use them again.