handed over after i have paid account

i dont understand why vodacom has handed me over to their debt collectors, its been months of trying to pay and writting complaints on hello peter and twitter and going to voda world. I was finally given the amount I owe of R705 at vodaworld and then i was told that i can not pay cos their payment systems are offline and i must do a bank transfer. on the 17th i did pay an amount of R710. But now VVM debt collectots are demanding 964 from me. Pleas rectify this and make sure that my credit record is clean and sorted out. <br>