Subs, Internet connection & billing

December 2014 neotel had a price decrease and those on a 5gig plan was migrated to 10gig at the same price of R149pm. However I was not migrated. After numerous queries never got any good answers. Further more that same December I get a bill for over R1500 and when querying never got a decent answer also never received a statement. If looking at my history prior to December my monthly consumption was not more than 3gigs pm as my wife n myself have 2gigs ea on our cellphones so only time we do use it is at night from 6pm to 10pm how does it get depleted? Still no answers from neotel. Now I have capped my service so that I don't exceed 5gigs. Now I can't use my internet as there is no connection was told to Goto a neotel outlet n get my device tested & it's fine. But still can't get to use my GIGs? Can some one help me please solve three issues. Thanks