Virgo:
If you have been on Rogers for 2yrs+, you are eligible for one of their "Hardware Upgrades". You'll get a phone at a cheap price, with the only catch being that they ask you to renew for (1 or 2) years. If you've been on that long, or use the phone for business etc, you're not likely to leave, so go for it.
If you haven't been, explain to their customer service what happened and if you're close, they'll still come thru. If not, tell them you are going to have to cancel your plan. They'll transfer you to the "Save That Customer" Dept, and they'll most likely help you out with a phone.
If all that fails, buy a 2nd hand Rogers GSM phone (as you don't have to worry about some of the account issues EotD mentioned above), then go to a Rogers dealer and have them convert your account to GSM. It's most likely the cheapest way if all else fails.