Need some advice pretty quick

Took advantage of an early black friday sale and bought some bulk ammo online. 1500 rounds total.

Tracking said it would be delivered today, according to the UPS site it was left at my door at 6:23pm. At 6:33 I checked tracking, saw "Delivered" and found nothing at my door.

Not really sure what to do here. Until proven otherwise, I feel like I have to assume it was stolen from my porch. Should I call the cops? Seller? UPS?

If a gun had been stolen, I'd already be filing a police report, if it was any other non-firearms related product, I'd check with the seller and UPS first.

In this case a large quantity of ammunition is missing. Call police?

Update called UPS, got pretty much nothing. Contacted seller, they're going to "initiate a UPS investigation" which will take 8-10 business days. Kinda pissed