Unauthorised unsuspension of Simcard

I have suspended my 2 data simcards with Autopage during May 2015. I also have a block on the simcards to limit data usage to R750. I have not used this specific simcard, although I had the simcard re-issued after it was ****** in July 2014. Out of the blue I got an account for R6 456.55 - normally it is R238.00. When I phoned and questioned the account, Autopage Call centre told me that it is not their responsibility and that the R750 block does not work. I have not made those calls. I have not ASKED the simcard to be unsuspended. Since the 21 September 2015 I have been trying to sort out this mess. I have emailed approx 30 times - because you must notify Autopage of a dispute via email. I have phoned almost as many times. But have not received any reply up to now. I have asked them to split my account and also how can I cancel my account with Autopage. No reply. What must I do to get a response from them and to assist my with my query?