Never. Use. Amazon. For. Pre-orders.
Now you've learned the hard way like i did. Never again will i use Amazon for pre-orders. They fucked up on me back when 360 was still king and I'll never use them again. SimplyGames or ShopTo are the best. I get all my games early.
I've had bad luck with amazon. This time I ordered just a few days ago (I usually order months ahead when I can) and it's out for delivery. Last few when I ordered super early they've been late.
Went through it with the Switch itself and again for MK8 and fortunately, they got it right this time with Splatoon 2. Still waiting for UPS to screw this one up though. We'll see when I get home later I guess. Preordered in April.