Well, I'm not sure if it's Amazon or the seller, but DH ordered t-shirts that I found cheaper elsewhere, so we canceled his order less than 24 hours after it was made. We recieved cancellation confirmations from Amazon and both sellers, but one seller still shipped his shirt today. I went back in and canceled the other shirt, that hasn't shipped, again.
Side-note: I schooled DH on Saturday about being a moron and that Amazon is not the be-all, end-all in online shopping. He was paying over $50 for 2 t-shirts. I found them for ~$30 with shipping. Mor-an.