so someone owes you a significant amount of money from a business relationship they decided to end. they signed a contract saying they'd pay X amount upon termination, but are balking at that because they claimed you did not wholly hold up your end of the contract (which is extremely debatable). you sent an email refuting their claims but agreeing to compromise on the amount of money 10 days ago, and have heard nothing in any form since (the rationale for waiting so long--they generally suck at communication, and you were giving them the benefit of the doubt about just mailing a check on their normal pay day).
how much longer do you wait for contact/money before contacting them again? do you send a nice/courteous email reminder or do you let the bitch out and threaten court at this point?