VERY UNSATISFIED AND WILL NEVER PROMOTE VODACOM

I have paid and cancelled my contract in Dec 2018 after being told that my account was in arrears which i disputed but still ended up paying which lead me to cancelling the contract. they explained to me that the contract will only be cancelled end of Jan 2019 which i still have to pay for Jan 2019....ohk no problem, i payed double again in Jan 2019 just to get out of the contract... now its march 2019 and this people is telling me the same B.S about my account being in arrears and thats why my account wasnt canceled and they still billing me. What B.S is this??? so does that mean all the efforts i made to cancel this contract is all for nothing and that vodacom just expects me to pay? where do i draw the line? im currently doing research on finding out what i should do and how to go about doing it because im NOT giving them another cent of my hard earned money because your favourite words are "ACCORDING TO THE SYSTEM YOUR ACCOUNT IS IN AREARS"