I've been buying cards and lately they've been sent with "ESUS" tracking numbers. They're all sent from within the US. They always say "Delivered" but they're never delivered that day. They don't say delivered to my address but just to my zip code.
Usually they show a day later, but I had an order that said delivered on Wednesday and it's still not here. What can I do? I have no clue what carrier to contact because it's so vague with the tracking number.
That is eBay's standard envelope tracking. They don't get scanned upon delivery, so the delivery date is estimated based on the time they get scanned at the destination post office. Many times it's a few days off. Since the tracking number is proprietary to eBay, USPS won't be able to help with it, so if it doesn't show up you'll have to file a claim through eBay and get a refund.
eBay takes awhile to update the tracking on the site.
Tracking is not through USPS, it is with EasyShip. You can get more current and accurate tracking on the EasyShip website:
https://parcelsapp.com/en/carriers/easyship