Wireless Data Spikes

Question

I have looked at multiple posts from people experiencing the same issues we are experiencing here at our house.  We are seeing enormous spikes in data usage during times when we are not home and the computer is off.  We dropped our ATT DSL connection and signed on to Verizon in mid January.  We signed up for 6GB because we do not stream videos or music, have no kids and work far too much ... Our dog is extremely smart, but does not have opposable thumbs and her paws are too big, so her computer use is nil.  We immediately saw massive data consumption that forced us to up our data plan ... Three times.  And still went over the plan only to receive a $90 surcharge, most of which occurred on the last day of our billing cycle so we had no chance to adjust the plan.
Finally after watching similar spikes occur again this month, we went to one of the local stores.  I was in line at the local store for about an hour until I finally spoke with a sales person who said that we need to call in and talk with Verizon Tech Support ... What fun that was!  After forcing my way through the automated system by pressing "0"multiple times, I got a customer service rep who finally connected me to nice young lady who tried to be helpful, but essentially talked in circles about something trying to contact Comcast through our modem, to the point of even asking if either my wife or I work for Comcast ... We do not work for or have any affiliation with Comcast, nor am I remotely aware of any possible connection to Comcast from our home.  During that call, I reset the modem and made sure all devices were disconnected ... We still saw a spike in data usage.
I turned the modem off on Monday evening at 1030pm EST and that seemed to stop the bleeding.  I turned it back on yesterday afternoon just to see what would happen ... No huge spikes yet, but that hardly seems like a solution to me.  We want to be able to use our devices when we want to use them, not on/off/on/off every time.  Considering the other posts I have read, I feel that our best option is to drop this service, pay whatever penalty to break the contract and revert back to another ISP.  This system is not worth it.  Worst of all, it is actually slower than the old DSL we had before.
Bottom line is that we are completely dissatisfied with this option through Verizon.

Answer 1

I have done this and it shows which apps are using the cellular, however none of them are using near this much.  I think the one that had the most was 500meg.  Not even close.  Is this perhaps a provider issue?  Or a virus maybe?