I don't know if it's illegal but it certainly is stupid not to take cash! I can see not taking a check; you're essentially exchanging paper, although cash is paper but you get my meaning. Unless you pay your credit card balance in full, you will be paying interest on that gift card and that's just plain wrong! Could you have put it on your debit card? That way it comes directly out of your checking account. The whole thing is irritating to me and I'm only reading about it! I don't blame you for being upset!