Vodacom Bad service

End of October Vodacom deducted almost R3000 from my bank account. I contacted the Kalahari Mall Branch in Upington to query this because this was where I have upgraded my data account. I was told that I have "an open contract" This was after I had the ugrade for more than 2 months and had to purchase data at their store after my data was depleted and after I had to go back to the shop to have the night owl activted. Recenty I received an email from Franco Snyders from Vodacom Kalahari Mall telling me that it was his fault and my Vodacom account will be credited with the amount. This mean that I have data woth almost R3000!!! I told him in my reply that they took the money from my bank account and that I want it back. I do not want a data credit!! Since then I've had no response from them. how can you just take money from people's accounts without their consent?