I had the same problem, a few weeks ago. They had sent my pigeon to the wrong depot, because of my work pattern I aranged to pick up (after they located the bird) at my local depot.The manager rang me at 5:30am (agreed the time) to confirm it had arrived.
When i got there i said can i have a claim form as I was angry and £25 is a fair whack to pay for 24 hour delivery, for things that dont arrive on time.
Any way he said take the bird and forget about paying as it was Amtraks fault.
Get a claim form if you have paid, or complain to the head office
Amtrak Express Parcels Ltd
Company House
Tower Hill
Bristol
BS2 0AZ
Tel: 08705 456 456
Fax: 0117 933 7763