Pathetic service

Pathetic service, My contract expired more than 6months ago and I eventually cancelled so it can stop deducting. But my credit score keeps dropping because Vodacom says shows I still have an open contract with them and its not paid. Why and how would I pay for something that lapsed and was also closed. Bunch of ****mers, very hard to find a human to speak to on their CC lines Ive tried for months and months