Based on user submissions all order numbers from the 17th of September were starting with 586. Orders didn't reach 587 until the next day. Can you double check both the date as well as the order number in case you miswrote either one of them
Both were direct copy and pastes (with the last two digits of the order number then xxed).
To summarise:
I ordered on Thurdays and after fighting the site finally got it in at 15:16 (and 50 seconds according to the email). My OC order number is OC40254xx. I've also been posting here over those few days, I understand how the system works for the unofficial tracker.
I was stuck on "New Order, Awaiting Payment" until sometime between Saturday and Sunday, though the money had gone from my account immediately. That is presumably on sync issues between OC and their payment provider (credit card for me, so braintree) during the site getting ddosed by all of us trying to order.
I didn't get any emails, either order recieved or the update on stock levels until 17:48 today. Based on the estimated place in queue on the tracker, and the google sheet's estimate for total orders of the MSI Gaming, I suspect my order number in the system that uses numbers starting with 5s wasn't generated till they sorted whatever set of orders hadn't gotten emails yet and caused the deluge that we've heard of in the last few pages.