same happend with me had the scooter outside and looked it was there got ready to go out about 5 minutes later and it was gone, safe to say i never saw my scooter again it was locked to a fence too, you need a ground anchor and always needs to be locked onto some sturdy, just locking the wheels won't do shit they lift the bike and its gone.
sorry to hear it dude, get on the blower to insurance.