You should deposit the check and not bother going after the $270. Even if you win, there is no guarantee that you will collect it. In fact, it sounds like the other party knows the routine and has frustrated you so far. In the future, you should refer the matter to an attorney 30 to 60 days after it is late. Most collection agencies can only send letters or make phone calls. They cannot sue the debtor and you just waste time trying to collect your money. Either ask your business attorney if he does this or find an attorney who handles collection matters.