I work for a dealership that uses the same system... actually most dealers use this system. They are "dealer catalogs" provided by the web servicing company called PSN. If you look at the bottom of almost any dealer's website you'll see "Powered by PSN". Just because you see a part in one of these catalogs doesn't mean the dealer has it in stock. It simply means they can get it. If you check Ma's site it probably states that it can take up to two weeks for your order to get to you because of this reason. As far as your order not being processed, they were probably just waiting to charge you until your items came in and were ready to ship. Kind of like when you order something that is on backorder, you generally aren't charged until the item is ready to be shipped. In this instance I don't know if this is definitely the case, but it most likely is.
In the future if you want something immediately, your best bet is to call the dealership ahead of time to make sure the item is currently in stock.