Call now, they're 24/7 I believe. Usually they need to know where the package is. If it's on its way, you're stuck waiting, but if it's not, they can switch, which is why I say don't waste time and call now. I've spent the last week dealing with their support because their payment system felt like it went to shit this week. Whatever you do, be polite but firm and mention how you only ordered because you knew it would be coming in two days.