Canceling a contract with bell?

My bill with bell raised 58 dollars, and it's only been rising. It says I'm using data I didn't know I used. Can you even use internet when you're not on an internet plan, or connected to any wifi. In addition, I have a feeling facebook has something to do with it, because I keep getting mail from facebook on my phone and I don't know how to stop itt!! I'm fed up and want to cancel my plan all together.

How much does it cost?? I have a phone worth 600 dollars on a three year plan and I've only had my phone for six months. Costumer service sucks. The last phone I had was stolen, and the other one began having technical problems (I've never dropped it). So now in addition to my phone I have now, I have two phones that I'm still paying for on the side. AAAH I hate bell!!! How much does it cost to cancel all my plans. I honestly have no care anymore.