To make it work temporarily, screw in one or two small screws between the ring and the post. Use vice grips or something other than your hands if you attempt to cut off the bolt with a zip cut. Be careful.
Or use vice grips to grip the ring onto the post until you can get it fixed.
Edited.. I see the latest response.. as I understand it, the clamp is on the battery post, but the threaded piece that holds your rings is stripped. If you have an old fork, bend one time out and cut the other two short and sharp. Then force it under the nut between your rings. This will put pressure on the nut to come off the threaded post.