Anti-theft system

My keys were stolen and then the car was stolen also. Then the car was found later and my keys were in it, but the anti-theft system had came on and now I can't get my car to start. I think another problem might be too it's a key-less entry and there was no key given to me when I purchased the car for the door just the ignition key. I've tried several different generic ways, for anti-theft system reset but it just won't work. I need to know if there's a specific thing I have to do with this car. Please I need your help.