have the same problem
If you use the pole every day 5-6 days a week two things happen first the pole section inself wears second the clamp wears, I have in the past taken the clamp off opend the clamp and sanded(with a grinder) the gap so that it can be tightend, this only works for a short while, the best bet would be to buy a replacement clamp/clamp lever/and nut
again this is only a short term solution as the pole section tends to wear out faster because the clamp is new,
I find that my pole lasts about 6 - 8 months then its time to replace
http://www.gardinerpolesystems.co.uk/acatalog/shop.htmlJust had delivery from above two replacements and one complet pole will try tommorrow but they look good and are the cheapest (of this quality) I,ve seen
At these prices if the pole only last 6 months it at 5 day a week the replacement sections average out at about .50p a day