It is funny, I had the same experience. Actually I just created a login here so that I could comment on how disappointed I was with the service. I purchased over $1,000 in cards through Bitcart.io and more than half of the cards sent to me (by the way which usually took over 24 hours each) were already found to have been redeemed by other Amazon users and therefore not deemed eligible by Amazon. Please use with extreme caution.