Not getting any help

USED to have a contract cellphone with Vodacom. And i was using this number***)for contract and I finished paying Vodacom and they are no longer debiting my account.i don't owed them anymore since April this year..But they are not clearing my NAME.EACH and every time i try to buy something on credit..ITS VODACOM VODACOM ALL THE WAY.and every time I call them they send me a settlement letters which is not helping me ..Can you please clear my NAME. AND ITS ALSO AFFECTING MY CREDIT SCORE ..