I wouldn't be too hard on them. I run a E-Commerce web site, and with all of the credit card fraud lately it has become much more difficult to charge international credit cards. Trust me, they wanted your sale, but it was just too difficult to complete. What I assume happened is that their credit card processor will not accept a credit card that does not have a United States billing address, basically if you credit card bill doesn't get mailed to a US address your screwed.

Our company had to stop selling to Canada because its very difficult to verfy the credit card the customer is using is not stolen (we got burned a time or two.) The other problem is when we ship to Canada (UPS) we have to fill out extra customs forms and have two copies of the invoice to send with all this documentation. A normal shipment takes about 30 seconds to complete and a Canadian Shipment takes about 8 minutes, that hurts when you could have had an extra 16 packages out the door. We tried to ship via the postal service and it takes FOREVER, and there is no delivery confirmation.

Like I said its not that they don't want your business, its just that its risky and time consuming for them.