We put something buried in our TOS that says "You agree to contact us in the event of a customer service issue or incorrect charge, and give us 15 days to resolve the issue BEFORE requesting a chargeback from your bank. If you do request a chargeback before contacting us, you agree to pay us an administrative fee of $100 plus the cost of the chargeback.

I've never tried to actually collect the $100, but what it has been useful for is the guys that say "Do (whatever) or I will request a chargeback" and, after I point out to them that they've already agreed to the fee, usually they back down.