I have recently received notification that I was underpaid by quite a considerable amount for 2009/10. I've tried to contact the Helpline, but it's always been busy. It seems a bit too good to be true. I knew I had been underpaid slightly, but not by this much.
Does anybody know how underpayments are paid? Will it suddenly appear in my bank account one day? If so, how long is it likely to take?