Either way, he said that mark had nothing to do with guard. Not entirely true. Guard directly effects how long mark lasts. It was my mistake on the tooltip, the relationship is reversed from what I thought it was. Soon as my guard is broken I always use at-wills anyways so it always happened at the same time for me.
They paid with their wallets, that doesn't mean that you can't pay with time. If you are mad they can succeed by spending 450 bucks, then do the same. Otherwise start grinding out those diamonds and pvp points.
Not exactly true, but very close. At wills used while guarding don't remove your mark. If you notice, when you use your at-wills while not guarding, your mark goes poof rather quickly. It also mentions this at the bottom of the mark tooltip.