The ClaimMyRefund service checks your Oyster card journeys every 48 hours. Identifies and submits claims on your behalf, keeping you updated by email. Up to 21 days later you will receive your refund voucher in the post.
I believe every Oyster card customer should be reimbursed for delayed tube and DLR journeys as quickly and easily as possible. Other refund systems rely on you recording details of your journeys and delays yourself, taking valuable time and effort which probably explains why in 2011 £20 million of refunds went unclaimed. This service is different, it submits refund applications without any imput required.