Stay away from this crummy company - Cardpool.com. It was bought out by Blackhawk Network - the worst company in the gift card business. Their corporate number is Phone: 925-226-9990 but it's completely useless, they don't care about customer service issues.
Cardpool itself is a total scam, they don't have a physical office, their calls are routed to disposable cell phones, and they only have 2 employees - Anson Tsai (the owner - cell 415-269-6147) and Jeff (order support - cell 925-337-5811). The whole operation is linked to a PO box but all the action is happening at the owner's condo at 660 King St #223.
They will lie to you, hang up on you and even block your number so you can't call them. Read the reviews online, they've stolen thousands of dollars from customers' gift cards, going so far as blaming the post office, when the post office has provided video footage showing them taking possession of undamaged envelopes. You've been warned! DO NOT LET THEM GET AWAY WITH THIS!!!