Vodacom ****

I had a R80 data contract with Vodacom. Last month They debited more than what I had agreed for them to debit so i reversed the debit. They locked my phone I could not make any calls, mind you this phone is not on contract. The contract I had was for Data. After a month they decide to open the phone but they have taken all my airtime and data and still send me an sms saying I owe them R342