Click fraud really "sucks" but the thing you have to do is track every single visitor and see who is clicking your adverts and when.
If your advert is getting clicked at a steady rate tehn all of a sudden 100 clicks in a minute, you know something is wrong. Just try and be aware of all your visitors, and ask yourself, "Why are they not buying anything or using our services" Could it be because of your website or just because they are fraud clickers?
There are loads of possibilitys. Good luck finding out what your problem is, and destroying those click frauders
Mark