Continued Billing After Contract has Ended

I was called beginning May 2015 by someone from Mweb who pointed out that my contract was coming to an end soon, he then asked if I would like to renew and I said NO. I made it very clear that I have had no use for the data in the past 12 months due to lack of network in my area. I then found it strange that I was still being debited end June and that is when I called the call centre to enquire. A gentleman told me that the process was handled incorrectly and my contract was supposed to be ended immediately. He then cancelled it but pointed out that it would be in effect end August. I told him that I disagree with that and he agreed with me and said I should take it up with accounts and billing. After sending numerous emails to Mweb accounts and billing NOBODY has since contacted me yet they're still debiting my account. THIS MUST END NOW. I need to take further action against Mweb.