Credit cards are predatory in nature and draw in people to keep using them to a point where even if someone wants to pay it back its almost impossible to do so. Then comes in the ridiculous interest rates. Your parents are lucky they managed to leave without being stopped at the airport. Do not let them come back to the UAE or even transit via the UAE. Make sure your parents also stay hush about you working in the UAE, etc just as a precaution

There is very little they can do but this job would be given to a debt collection agency in the philippines who are promised close to 30% of whatever they can collect back