Bests & Worsts Reviews from Amazon

The card was just wonderful and such an easy experience to purchase and send to a loved one. However, something happened that I never would have foreseen: My son, the recipient, called me when he said he tried to use it for a purchase, and was told that someone had already used it! He contacted Amazon and told me that they would send me a refund so I could then order him another card. To date, I have NOT heard from Amazon regarding this absolutely unusual and unbelievable experience. Certainly Amazon should be able to tell 'who' used this particular gift....and I should have received my refund by now. Please advise. I want to continue to purchase e-cards from Amazon and have every confidence that this will never happen again. Thank you.