I love cardpool and the only reason I'm here is because when I googled cardpool "complaints" was one of the top results. That really surprises me. I've been using cardpool for 3 or 4 years now and have never had a problem unresolved. One time I bought a Christopher and Banks card and the number didn't work on the C&B website. I emailed cardpool and my purchase was immediately refunded with no problem. I typically buy Home Depot printable cards and receive the card number at virtually the same time as the order confirmation. This last Sunday though I bought $150 of printable PF Chang's cards thinking I would use them the same day. Unfortunately, I didn't. I don't know if they don't work on Sundays or what. I emailed them on Monday morning explaining I no longer needed them. The canceled the order with no problem.
My one complaint is that physical cards are now being sent via registered mail which is a pain because I'm never home when the mail is delivered so I have to go to the post office. I now stick with printables and electronic only.
I have never sold gift cards through Cardpool so do not have any experience with that aspect of their business but buying has been great. A wonderful way to save money on home projects!