Where did my data go Vodacom

The giant mobile network operator used up all my data in one day when I was hardly on my phone doing anything. I checked my app to see what has been eating up all my data and as it turns out peer to peer file sharing has been doing that. I don’t know what this is and I also know that I did not share files with anyone on the but there’s no way that could have used up 12 gigs of data in one day. A days worth of streaming Netflix doesn’t even use this much data let alone file sharing . Vodacom is really taking advantage of us and if this is how things are going to be then I will have to look for another service provider and cancel my contract