The Bungie Store is currently swamped with extra orders for the shirts and jackets.
When you place an order during times when they're not doing anything special, there's a lot less delay between the order being placed and the package being shipped.
If you received a confirmation of your order, then you just need to wait on it to be shipped, which may take some time because of all the other stuff going on.
If you want to contact the Bungie Store about your order, you'll need to use the contact form on the Bungie Store website, but keep in mind that, again, they're currently very busy with lots of things, so it may take them time to respond to the inquiry request.
Pretty much, for now, you just need to wait on your package to be shipped. Your order was placed so you're good to go.