Yes they can collect even if the account is closed. If they are unable to collect on the debt then the debt will eventually be handed off to a collections agency.
Most collections agencies will start by sending off some letters demanding that the person pay back the money they owe. Some collections agencies will even go as far as to threaten the debtor with jail if they don’t pay, these are just threats though.
Then the person may start receiving phone calls at home and at work, although these can be put to a halt with a cease and desist letter. If the debtor still doesn’t contact the collections agency or loan company about the debt, he or she could find themselves as the defendant in a law suit. A lawsuit could call for wage garnishment or property liens.