Data disappearing

I have a 5GB top up data contract. In February the data was depleted extremely fast, for no apparent reason. I purchased a 1Gb top up data bundle, which lasted 2 days?!? I then disconnected all my devices, except my son's cellphone and purchased another 1Gb top up. Guess what? It did not even last 2 days with us not even being home for the entire day. I phoned CC and they said we had been on the internet and was browsing for the day using up 1Gb. <br> This does not make any sense as 1) we were not home for just about the whole day and 2) browsing cannot use up 1Gb. One has to download extremely large files to use up that amount of data.Oh and all updates were also turned off.<br> Something is not right!!!! <br> Why was 5Gb a month always sufficient for our needs, and now 2Gb doesn't even last 4 days with only 1 device? <br> I am not happy.