Im so sorry dude. Mine got stolen right after I put new black rims, new swingarm, new bombshells, new frame on it ...... It was found by CamMclean cuz the guy was in Lake Piru with it, just advertise it, post pics if u have any, and put a police report on it.
Also, dont give up hope on it. Keep calling the police station to see if they have a 50 in impound. They returned mine bike to the guy cuz the frame didnt have a serial number and the serial number on the cases were grinded off. I found out about it and they ended up finding the guy.
Im not sure if you want to, but maybe put up like a 200$ reward with a picture of the bike, and hang it up all around your town. Chances are someone knows the guy who has it and will turn him in in a heart beat.
good luck getting it back. check e-bay because if they are dumb enough to steal a fifty maybe they are dumb enough to post it. my friend had his kids cr80 and xr50 stolen and it was their neighbor that did it. They hid them in some trees behind their house.