If a third person made unauthorized used of cash advances on your credit cards, you have the following options:1. immediately notify the credit card companies where there was an unauthorized cash advance and report the situation as a fraud and place a freeze on all of your credit cards;2. contact law enforcement about the situation in order to make a police report;3. contact the offender directly about the situation and work out some agreement in writing as to how he will repay the $20,000 plus taken from your credit cards;4. contact an attorney specializing in credit card fraud about the situation that you are confronted with for assistance.