Why is my package still in pre-shipment?

[Moogle]

I ordered something off a website on the 24th of October. I've been attempting to check the shipping status of it with the tracking number I received on USPS.com but the only thing it says is that it's been it's been in pre-shipment since October 30th, indicating they haven't received the package yet. I've already emailed the website about it and they confirmed twice that they have indeed shipped the package therefore it shouldn't be saying it's still in pre-shipment.
I don't intend to come off as impatient; I've simply never had something like this happen before. I normally wouldn't bother worrying but the last time I ordered something from this website it was here in under a week and the tracking number worked fine. It's taking over twice the amount of time it usually does to for my package to arrive.
Does anyone know why this is happening? Why is it saying my package is in still in pre-shipment if it's not?

Also, I would like to add I tried calling the USPS customer service numbers for assistance but it was entirely automated and failed to solve my problem.

[Skip B]

It is possible that it is being carried to your local PO by a third party carrier. Although most all carriers scan and download statuses to USPS, perhaps there is some reason they haven't. Or the company is simply lying and covering their butt. After all, it took them 6 days just to get it in preshipment!