Staff have no clue of what they doing

I came to game to take out a R100 contract and got declined has Vodacom claims that I owe money on a old account , after calling and querying it there’s nothing on the account but the system is declining me , I can’t understand this has I have a current account with Vodacom that’s paid up . I called them about 8 times and these people have no clue but they happy to pass you to another department and then the calls cuts . Worse service I ever received