Huge Bill Received!!

I received a cell phone invoice of R5468.61. I immediately logged a call on 21/04/2015 (***). My invoices over the last 20 years were never exceeded R1300! The consultant at Brooklyn Mall phoned the call centre to log a call (***). They told him that it was definitely a mistake as I have used just more than 1GB. I buy 2GB every month (R89.02 per month) which means that I have not even used all my data purchased in April. They also confirmed that I already received another 2GB for May. I never use all my data and it gets transferred for 2 months before it expires. My phone was cut of on the 7th of May 2015 and this is an error from Autopage's side. I am a commission earner and rely on my phone for business. I went to the store another 2 times, phoned 5 times speaking to lots of people at the call centre to only get transferred to another and then eventually cut off. The only answer I get from the branch as well as the call centre is that the case still shows pending and that it is still under investigation. Nobody can help me. In the mean time I am sitting with the inconvenience not having any connection with anyone at all. Use e-mail [Email Removed]