I caught Commission Junction RED HANDED commiting FRAUD against me a few years ago.
After sending them thousands of impressions for their eHarmony promotion I had serious doubts that I had "zero" signups. SO, I clicked my own ad and signed up myself (which you are allowed to do), and still their report said ZERO signups.
A CJ official gave a talk at Pubcon, and I confronted her after her talk, along with another person with a similar complaint. She gave me her card and promised to 'look into it". Not a word in response, and she doesn't answer my email.