Bad advice & billing

When I received large Data bills in June 2014, I asked MTN, which told me there is nothing I can do as the wifi contract is not cap -able. I didn't know many sites visited, suggesting someone was hacking into my wifi. It happened again in July 2014, Jan, Feb, March, April 2015.<br> Only on 1 April, when asking MTN for help regarding a R4,200 data bill, was I told I could 'migrate' my contract so that I could run my wifi as a top up system. Good call centre advice 8 months ago could have reduced the data costs I have incurred since June 2014. <br> On investigating the high data bill for Jan 2015, MTN said that I had been over-charged R300+. I was reimbursed, but if I didn't query my bill, I would not have been paid.<br> On 27th (@ 01.35am & 9.17am) & 31st March I received notifications about bought data which I know I didn't buy. This despite that on the 27th 1024MB were given to me as part of my contract. MTN says they have no record of a Data purchase for me on the 27th. MTN reimbursed me for the data on the 31st but if I didn't investigate I wouldn't have been paid. When I press *141# I am told I have 3.9gig of data on my phone when my contract gives me only 500MB per month