[Checkpoint]

I feel like they would have scanned the package upon receipt. The fact they didn't makes me hope that they just discarded it.
Hoping for the best!

Point is, I spoke with an indian girl who just had access to stuff through a computer. It simply said "the item hasn't arrived", because you actually have to put an identifying label on the package, so that they can assign the item to your order.
Of course the package has no special identifying label, this means that the girl would have said "the item hasn't arrived" even if the warehouse had received, registered and stored the package.

So yeah, I fear that doing a simple check with the warehouse through tracking, they will say "oh yeah, that package, it was empty" boom, fail.

Oh well, after a number of succesful refunds, one was bound to fail. I didn't think everything in advance sadly. I think the lesson here is clear.

Not boom, fail. Complain you sent the item. That it isn't your fault that they lost your package. Ask for proof of the empty package with your label on it. If you were an actual customer and you sent an item back expecting a refund and they just told you they didn't receive anything - that's clearly not right.

I will try to push of course lilke you said of course.

I spoke with an indian girl who just had access to stuff through a computer. It simply said "the item hasn't arrived", because you actually have to put an identifying label on the package, so that they can assign the item to your order.

Nonsense.

The tracking number and Its respective barcode that's scanned during transit and on delivery, Identifies sender to receiver and vice-versa. If there's no sender's label, the package will still reach Its destination and scanned with the consignor & consignee Information.

this means that the girl would have said "the item hasn't arrived" even if the warehouse had received, registered and stored the package.

This doesn't make sense.

How can a package that's been registered Into their Inventory, be deemed not delivered?

Because the girl said that "the ITEM has not returned", I hadn't given her yet the tracking.