My dad had a situation somewhat similar to this one day...
He had done a job for a guy who was really draggin his feet on paying him. Finally, my dad pretty much MADE him write him a check for the amount of the job (somethin like $2400 or somethin). Well, Dad went to the bank, and he verified that there was NOT enough money in the persons account to cover the check, so my dad knew the guy was tryin to get out of paying again. (this is where the genius part comes in)
So, my dad asked the teller HOW MUCH it would take to get the balance up to what it needed to be to cash the check, the teller told him like $300, so dad deposited $300 CASH into the guys account, cashed the check, and cleaned his A$$ out!
Oh yeah, the guy called a few days later with NO MONEY in the account furious as to WHY/HOW he cleaned him out, Dad just shrugged it off and said, "Sorry, I needed the money and you've owed this for over 6 months now". Dad would have rathered been out $300 then the entire amount of the job.