****** Data and overcharged data bills

First of all my average spent for the past months never ever exceeded R690. I'm in a wifi zone 95% of the time, so how on earth am I being billed absurd data bills for the past 2 months. First of all data which I receive on the 8th of every month goes missing after 4 days (miraculously). Spoke with a Vuyisanani Nakedi at MTN who is a Billing Queries Administrator who emailed me my data usage and websites that I've visited which means sweet buggar all to me because obviously I know I've visited sites ON WIFI and get told my charges are validated which is total BULL because that is MTNs favorite mantra when customers query their high data bills. And pls do not tell me about my smartfone handset as I'm not an idiot and know all about having my data switched off and don't have any apps updated or running in the background. Amazingly enough exactly a year ago I too received overbilled data charges, and after putting up a fuss and fight it was reversed and my monthly statements were back to normal thereafter...until now !!! This is ****************, MTN I'm sorry but after all these years of being a loyal customer, Cell C us looking like a better option for me. I will not pay this amount and my debit order from last month needs to be refunded/sorted out. And this is my calculation mailed to me by MTN : Invoice 2016-04-07 total data used = 3115.59MB-500MB-275MB (monthly allocation) 2340.59MB @ R0.87 (out of bundle rates) = R2036.32 (supposed to be charged) As per attached itemized billing customer was charged R2691.60 which is more to the usage calculated above by R210.94 which will be credited. So if that's the case then how on earth and who on earth does the calculating???? Does someone just suck numbers out of their thumbs????? U guys are ******* *****ing from us. This needs to be sorted out cause I've just about had it with MTN and their terrible service. My a/c no: A***