This doesn't make any sense. Why would a company intentionally screw over its customers over such a trivial issue? Their window is 15 minutes because of bitcoin

This doesn't make any sense. Why would a company intentionally screw over its customers over such a trivial issue? Their window is 15 minutes because of bitcoin's tendency to fluctuate in price. If the network hasn't delivered your transaction, there's literally nothing they can do. Shouldn't you contact the merchant for a refund?