Having someone advertise to you by word of mouth, and information presented on the internet, are two completely different animals. Assuming that something you're reading was typed that day is an internet no-no. If you're reading some ad someone has pinned up for "Buy 2 get 1 free!", the first thing you're gonna do when you call them up or stop by is ask if that deal is still on, not just grab 3 and hand them your card and freak out once you're looking at your receipt...

Could it have been clearer? Sure, but this is toeing a fine line between unfair advertising and demanding that your hand be held every step of the way. If you can't be bothered to do a little research and gotta have it now now now 'cause there's just no time and everyone else holds my hand, SE should too, then the fault doesn't entirely lie with SE.