Just a small comment on a recent purchase done on PCGameSupply. I have been using them for over a year for the purchase of Nintendo eShop credit, and had no issue whatsoever. Everything was fine until last month, when I decided to buy a Borderlands 2 game key from there. Since I had a pretty good experience purchasing there, I expected everything to go fine. Even when I tried they key and Steam told me it was already used, I expected them to replace. But to my surprise, they simply replied that I was the only person to receive the code, and that there would be no refund or replacement. Since I still need to use them for eShop credit and I only lost $5 in the transaction, I didn't make a huge deal out of it, but buying Steam codes (and probably game codes of other platforms as well) on there may not be safe.
I am glad that someone else has experienced a problem like this. I thought I was the only one who had had issues like this. I have not bought a game through PCGameSupply ever since the exact same thing happened to me. I wonder what causes this.