High Billing

My cell phone account has been an average of around R1400.00 for ages.<br> My march account shot up to a massive R4500.00 odd rand. when I queried it I was told that my data usage was high.<br> I have Wi-Fi at work and both at home. I never received a satisfactory explanation and just paid it.<br> The following month was also a massive R4500.00 odd rand which again I queried it and once again was told it was due to high data usage.<br> I spoke to an MTN agent and was told to turn off all cellular data/notifications which I did.<br> My next month billing shot up to a whopping R7500.00 once again I queried it and again was told that my data usage was high and that is where it went pear shaped.<br> Since then my average billing has been around R7500.00.<br> I try everyday to get hold of someone I can sit for hours tryimg to get through to someone.<br> I dial 808 and follow the voice promts only to get cut off. I can phone up to 25 times a day to get trough with no luck.<br> Now I sit with a massive outstanding account.<br> how can my average billing go from an average of R1400.00 to a massive R7500.00 when nothing has changed.<br> All my updates are done while on WI-FI.<br> absolutely disgusting service form MTN