Your customer DEFAULTED on their agreement. Even if they end up paying, they still did not pay on the agreed terms since they bounced a payment. The idea that because they are paying now makes them not a default is crazy. If a merchant stops on the first payment but 3 years later pays in full, that is still a default. With that being said you seem to know a lot about the law. Maybe you would do better in that line of work. Clearly this isn't for you.