Prepaid sim card changed to Contract without my consent

I was Highjacked without even knowing that my Prepaid Sim card in my Phone in daily use had mysteriously just changed to a Uchoose Flexi 55 contract, If it was not for me going to a Vodacom shop in Alberton to find out why my Email stopped working i would never had known, apparently RMCS at your Edgards and Jet Stores have a Vodacom satellite Computer to allow contracts, after all the complaining i don't even get an apology or explanation as to how this can happen. This is Disgusting service and incompetence at it's BEST, i expect an explination and who is liable?