Can you send it back to the manufacturer? That's usually the best way to go about it for production knives. Having somebody fix it is usually more expensive than the knife itself (if it's a mid priced knife).
Can you post any pics? That would help. There are a few guys who modify and fix folding knives, a picture would help know whether one of them would be the guy you need.
Now hatred is by far the longest pleasure;
Men love in haste, but they detest at leisure.
- Lord Byron (George Gordon Noel Byron), Don Juan
(canto XII, st. 6)