I recently took out a mobile contract with Vodacom

I recently took out a mobile contract with Vodacom. My phone was ******, reported it to them on the 27th of April and requested for a block on both the sim card and phone. The block was added and removed. After a few days I noticed the sim was being used and contacted them only be told the block was removed and there's no explanation as to why. An investigation was logged. The block was only added on the 5th of May, by then the bill had already reached over R4000. Promised many callbacks by agents and managers to this date, none have been returned. Emails have not been responded to either. My debit is due on the 1st of June and I was told the bill will be wiped off as it is Vodacom who failed to assist by blocking both the phone and sim card. It takes them more than a month to solve a query. Managers are useless and don't follow up either. This is pathetic service. I will never use or recommend them to anyone. I want answers and my bill to be wiped off as promised !