what a pain in the bum for you! The system will detect that your CCB debt has been overrecovered and they will reissue your $30 - you shouldn't need to do anything but it may take a week or two for the system to detect it and for someone to follow it up. Most likely your repayment hadn't yet been received in the system (can take 48 hours or so if you pay via bpay or post office) when your FTB payment was issued and it has been automatically deducted.