Where is my data???

My data has disappeared from my account 3 times in the past 3 days. Why am I buying data that gets used up with no app open and no activity on my side?! I want my data or this is going straight to Icasa. Im tired of this **** network. First they have no coverage 90% of the time. When they do, now they take my data. I want my data back immediately!! All of it!