Suprise Open Acc

About 18 Month ago I renew my data contract on Vodacom Special for R89 Top up. Now on the 30th of April the stop order went of for R1553.09 . I phone Vodacom customer care to find out why that big amount went of my bank account. Ref ***. Happiness' from the customer care told me that I have an open acc. I told her that it cant be, because every month my account is R99., She advise me to go back to the shop at Highveld Mall and talk to the Branch Manager . I went to the Branch on the 1 and 2 May , Jacques at the the store help us because the Branch Manager was out . Jacques sent a request through to customer care on the 7 May. But till now no luck from anyone. It is already the 13 May and the end of the month is coming. What must I do ? I cant pay that much money for nothing, because I did not signed for a open account.