Vodacom Bad customer service

On 15 December 2017 I requested to have a contract cancelled prematurely I did all they asked accepting the quote etc, the call reference for that day was 639193 on the 18th I forwarded the signed and accepted quote and because over the length of the contract I paid more than the invoice amount Vodacom owed me money and I was advised the money that I have in credit cover the outstanding amount and cancellation fees. To my surprise I received a new statement for the following month contacted their dreadful and horrible call centre manned by rude individuals I was advised I need not worry ( no reference for that call) End of February 2018 I get another invoice on the 7th of March 2018 I contacted the call centre again spoke to Sibusiso Reference number ********** 62 he told me he will fix my problem , but at the end of March I got another statement I again called their contact centre with rude staff and where you hear the loud conversations of other people in the background , even though this thing is cancelled and paid up I am stilling paying the invoices as these companies blacklist you immediately even though it gets sorted out afterwards the listing stays on your name