More often than not a replacement clamp will cure this situation.
If the pole is only spinning on one section (perhaps the top 6") then you may need to build up the surface of the pole by way of a temporary solution. To do this mix up a small amount of rapid epoxy resin and smear on the worn section, making sure that you scrape most of the glue back off before it sets. Leave overnight and then sand the glued area smooth. This should re-build the worn section of the pole.