BIS included in contract

I called the call centre to deactivate my BIS on 22 November 2015. I was advised to call back on the 01 December 2015 in order to reactivate the recurring BIS. To my dismay, I was told I will be liable for an additional monthly BIS charged to my contract. I informed the consultant that this is included in my contract. She informed me that the consultant who assisted me on 22 November 2015 removed the BIS, hence the additional charge. I asked them to check the initial contract again. They issued me with a reference number and informed me that the matter take 2days to be resolved. Well, its taken me 3 calls to the call centre and 7 working days later and no response from the Back Office team. At this point I'm fuming....