Mtn disappointing service

I had bought R40 airtime on the 8th of August 2015 which i then bought 300MB for a week which left me with R5 airtime. I had tried to go onto Internet only to realise the service was down. Which is understandable. The problem is this morning i looked to see how much data i had and it was all gone. Now i know for a fact there is no way i used any of my data let alone my airtime. I phoned customer service at around 9:30am only to be told it has been used by a background application which is ******* as i have proof on my data usage that i had used max 30MBs. The gentleman who helped me had no experience as i waited for so long just to be told that it was my doing for my data being used up which is impossible as i could not even access the Internet. I am really disappointed as i have been a loyal customer for years and now i do not know if i want to further this journey any longer. Please mtn resolve this issue. As i want my data back that was ****** from me.