WHY does eBay allow large sellers to use different shipping than the listing says?

[theguitarpartsguy]

I recently bought a computer mouse, I bought from this particular seller because they say in their listing that they ship via USPS first class mail.  This is important to me because there is NO DHL delivery in my area, so I intentionally AVOID sellers that use DHL for that reason.  Well, the seller of the mouse I bought actually shipped via DHL instead of what the listing says.  A week later, and my item is STILL not here even though it's only coming from a couple states over.  This is ridiculous, and I guarantee you that if any of US small sellers did this we would be called to the carpet on it.  I sent the seller a message which went unanswered, which I figured it would, but my intent is just to open a return and buy elsewhere once it (if it EVER) gets here.  eBay should NOT allow someone to ship via a different method than what's posted unless they change from a basic to a PREMIUM/Express method. 

[stainlessenginecovers]

It is NOT "allowed"; but it is also not policed. Guessing this seller is really in another country (using DHL) even though they say they are in XYZ (sometimes they have a 'warehouse' or an 'office' with that local US address even though they ship from elsewhere). 

So- again, it is not allowed but also no way to 'really' report it (so even 'small sellers') would 'get away' with it. 

[theguitarpartsguy]

Meanwhile, the item has been bouncing back and forth between St. Louis and Cairo, IL for 5 days and I don't live in either of these towns.  ALSO meanwhile, it was originally scheduled for delivery on 10/2, and NOW when I tried to file that I have not received the item, the delivery date has been changed to tomorrow and it won't allow me to file that I did not receive it on time.  What the actual heck?  So eBay just moves the delivery dates around to accommodate big sellers and we have no choice but to simply put up with it?  I realize that it's out of the seller's control once in the shipper's hands, but first off, changing shippers AFTER the purchase, and then extending the estimated delivery date more than once and not allowing the buyer to make any kind of claim?