Rash promises to pay after Gold Card’s returned right away (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

IOUS(or “I owe you”s/promises to pay) placed after ( after ) [ AU(symbol for the chemical element, gold) + reversal of ( …’s returned ) “ Card ” minus ( … away ) “r”(abbrev. for “right”) ].