As for the wording I chose, I said ebay is letting me down because I feel a $5 credit for a $400 item is kinda lame but I guess it's not their fault the seller/shipping messed up.
ALWAYS read the auction/listing details:
"* The delivery date is not guaranteed until you have checked out using an instant payment method. If your Guaranteed Delivery item isn’t on time, you can (1) return the item, for a refund of the full price and return shipping costs; or (2) keep the item and get a refund of your shipping costs (if shipping was free, get a $5 eBay voucher). Attempted delivery on or before the guaranteed date will be considered a timely delivery. "
You can read more about the eBay Guaranteed Shipping here - https://pages.ebay.com/shipping/guaranteed-delivery.html
In a nutshell when the seller enters into the Guaranteed Shipping program all they are saying is they will ensure to get the item out the door by a certain day. eBay then figures out how far the seller is from the buyer and how long shipping "should" take and thus comes up with the guarantee date.
So long as the seller has shipped the item by the predetermined date agreed upon eBay they are covered.
At any rate it sounds like you now know your options. Either take the $5.00 credit or return the truck. See eBay is taking care of you after all.