Over billing

In the beginning of the month vodacom phoned me and offered me a red premium package because of my data usage at that point in time it sounded like a better offer but never indicated to me that they would bill me on top of my existing bill they billed me my old bill plus the new tariff amount now my account is R3200 and I am on debt review so money is a thing I really look at and try to budget out but not for that now my line is blocked since the 13 Oct and they gave me 7 days to pay like if anybody that is on debt review can **** out R3200 in 7 days they dont even want to give me a chance to pay them off 7 days or blacklist thats my only options. I am done with them I will not pay that extra R1500 of the red premium **** they offerd me and they dont want to cancel it not before I pay. Please need your help and hope that everybody see this.