If you already have a lawyer involved to discuss your options, I would not do anything until after that meeting. Taking any action now could end up costing you

If you already have a lawyer involved to discuss your options, I would not do anything until after that meeting. Taking any action now could end up costing you instead of helping you. I can understand that you want "revenge" but that reaction can end up hurting more than helping. I hope this is isn't the case, and I don't think it is, but your post comes across as "This will teach them to screw with me!" IANAL, but what I would recommend is talking with your client (calmly) to come to a mutually agreeable resolution. This may mean you compromise on the remaining balance to some extent. What you spend on legal costs to pursue not just financially, but in time spent fighting with it, will far exceed any reward. Also, if you have a signed contract with them in the first place you can use that as leverage to negotiate the terms of a settlement. Most well-written contracts should have a clause in there regarding non-payment and the process for handling that. If that your case you can use that as leverage to negotiate with them. Nobody wants to go to court so they have an incentive to get it resolved as much as you do.