The whole cancelation policy, etc should be on the documentation you got when signing up for the 3 year contract. Its it not really posted anywhere on the website, as the contract and terms, have changed every once and a while, so what mine says and yours says, may be different..
There will be an amount, you will have to pay for ever month of the contract that you have left (so 26 odd months?), plus for full cancelation, i beleive there is a set cancelation fee.. i dont remember what it is though.
You would be best to talk to someone on the phone, or in a rogers store, they can look up this information for you, you are not likely to find it on the web. Only place that MIGHT have some info, would be in your myrogers section, if you have your cell phone added to it there.
your deposit will be credited to your account, they will likely charge you the full value of the phone and i believe its around 20/month for the duration of the contract (so around 520 dollars) for breaking your contract....unless you are getting horrific service, or a **bleep** of a good deal somewhere else, id stick it out and year or so at least