Using someone else’s credit card information to buy things without their consent is a form of theft. It doesn’t matter that you are doing it to try to recover money you believe is owed to you. If you do that, you may find yourself with a criminal conviction and might even spend a little time in jail. I would certainly not suggest you do that.
You want the money from her, sue her in small claims court. Whether you will win your case is impossible to say. It depends on what the judge thinks after hearing what you and the ex-girlfriend present in court. Small claims court in most states is pretty cheap and the rules are pretty simple. So you don’t have much to lose by trying small claims court. And that’s the right way to do it. Trying to collect by using her credit card information or taking her stuff without getting a judgment and taking the proper steps to attach her property can cost you a lot more than the $200 you are trying to get from her.

