If you check the status of your case in the resolution center, does it say that it is your turn to respond? What Error message do you get?
For a return, you don't have to use ebay/seller generated label. You can use your own, i.e. you either go to the post office or print it online yourself.
Also, what do you mean by seller escalating the case to ebay? It is the buyer who escalates a case, for example, the tracking would show that the return was delivered and seller has not send a refund within ebay's time frame then you, the buyer, escalates the case.
The answer that you got from ebay may be a computer generated answer. Did the answer actually include the tracking number?
I presume, you have contacted the seller, did they agree to your return? After they receive the return, they do not have to wait for ebay to issue a refund.
So the bottom line is, if the resolution center shows that you still have to provide a tracking number, it means it is not in their system. BTW, try another browser and clear cache and cookies, this may also be a reason for an error. If this does not help, you need to call ebay about the tracking number. Also, you need to get in touch with the seller in regard to the return. Send them a message thru the resolution center.
