First thing to do would be to contact the credit card company and advise them of the situation. Tell them what you can afford to pay. Follow it up with a letter. if they decline your offer, contact MABS and ask if they will contact them on your behalf, maybe freeze the interest or set up a temporary arrangement. I'm assuming that you will attempt to get a job in the future?
If you didn't pay it then that would be irresponsible. they would try to find you, which would include contacting all your known addresses and your family home (do you want your mum opening that letter). in the end they may just wipe the debt, if they are unable to locate you, or they can apply for an enforcement order to make you pay when they do..
When you come home, you better not be back for years. as the ICB keeps your information on there for every bit of credit for 5 years after the loan is closed (if they are chasing you they may not close it for 2/3 years before wiping it off, thatd be 8yrs record possibly) would you really want to go away for a while and come back and find noone would give you anything, even an overdraft with a bank?
Up to you.