Sounds like you cannot disconnect the swing arms. Since the chains are loose there's no distribution pressure on the ball. If you raise the hitch you should be able to get it off the ball. That should work. If not, you should still have the final option pull the pin and move your vehicle forward... at least you can separate that way. Then when your ready to leave, just backup and drop hitch back onto the ball, or plug the hitch back into your vehicle and reinsert the pin. When convenient run it over to a local rv shop and ask for some advice.
If nothing above works, please explain why you can't raise it off the ball or why you can't remove the hitch-pin and pull the hitch out of your hitch receiver... please be verbose.