Misled informaton /marketing

I have 2 contracts with Vodacom . They have been a service and network provider to my family ans myself for years. Vodacom had called and advised that I am due for an upgrade, which I was aware of and had made the decision to cancel . The agent named lewellyn had a lengthy conversation and assuring me and my daughter that he has a 2GB data budle for R99 , which I opted for. Lewllyn confimred we would have to use prepaid airtime and was assured that a few times. I was recieving sms's on data limit exceeded . I then went into a vodacom store and the agent there advised , we were on an open line . I explained her , what had happend, and I asked for the recording of the call I was highly irate because, I work in a customer service role for a huge airline , and this was false advertising and knowledge to the customer , the bill has been run up which I disputed , vodacom minused a, certain amount, but carrys over a balance on my vodacom acccount. Who is liable for this ? How am I responsible to foot the bill, because of *********** staff. I have no time to be back and forth to a vodacom store , I am also a person that works and has a busy lifestyle . Vodacom has got me thinking weather I should be keeping them as my network provider. This occurrd middle of July 2017. I had to wait till end of Aug to use the package I was "offered". I think its unfair that I have to also have my line suspended , because of an oustanding amount due. All because of unprofessional ,*********** staff.