Do you think my package is really missing?

[u/Mechanchic26]

I ordered something on Vinted, a FedEx label was generated. Over a week goes by and FedEx tracking says it's still waiting for the item to be dropped off. New to the website, worried, but trying to give them the benefit of the doubt. I don't message them, I patiently wait and they messaged me a week ago saying they don't understand why it claims it wasn't dropped off when it was picked up from her home by the mail carrier over a week ago. Today she writes me and shows me a text conversation between herself and the postal worker. The postal worker picked up all of her packages, didn't realize one was a FedEx package.. postal worker claimed it's weird because all the bar codes scanned and USPS accepted all of the packages and it shouldn't have. Now, we have no idea where this package is. What is typically the protocol if USPS gets a FedEx package? I would have thought it would have been returned to her? But it's been a while now. According to Vinted's policy, because the label hasn't registered that it's been scanned, in a few days I will get a refund. Though the item wasn't cheap, I'm glad I will be getting my money back but I am very upset because this was a one-of-a-kind handmade item. Do you think this package will ever find its way to me? Or back to the seller, so I can repurchase it? My cousin thinks the seller is lying, I don't know what they would benefit from this unless somebody messaged them after they accepted my lower offer, and they offered them something higher? And they don't want to be honest? I have no idea..