They stole my iphone 4, and i don't have insurance, what do i do now?

On tuesday, they stole my iphone 4, and i have at&t, me & my boyfriend have an account together, its under his name, so i called him to let him know that my phone had been stolen, so he called at&t to disconnect MY phone line, but we're under contract, i don't want him paying 160 for 2 lines when i don't have a phone, so my question is, can i buy a phone from ebay or craigslist and activate it with at&t? How will i need to do it? Please help.

Added (1). Oh also i didn't have the iphone find my phone app.

Well, There's A App Called ' Find My Iphone ' You Could Use That App To Find Your Iphone And It Haved Worked For Couple Of Guys.

If you buy a used phone, so far I know this:

(1) You need a cell phone that can run on the AT&T network. (Not all phones can run on the AT&T network. Even an Iphone 4 from a Verizon plan can't run on the AT&T network.) So only buy a phone that had run on the AT&T network unless there's some real guarantee that the phone was on a compatible network.

(2) You need a clean ESN. If a phone is stolen or the customer had not paid their bill, then the used phone has a bad ESN and AT&T will not activate it.

(3) The big carriers (AT&T, Verizon, etc.) will not activate a phone that is not E911 compatible. What this means is that years ago, cell phones did not have GPS built in them and when people made an emergency call on the road, the police did not have their GPS location. But, we're talking many years ago (like 6 or 7 years ago.)