https://www.facebook.com/ebay— Message button in upper right on landing page.
It's not exactly a Facebook issue.
It's that the issue may be best handled by one of eBay's actual employees* assigned to social media Chats**.
And this one will phone you back:
https://community.ebay.com/t5/Selling/How-do-I-contact-Customer-Support/m-p/32016431#M1783851 -> Automated Assistant, type AGENT -> enter. You will then get more options.
The social media Chat accounts are covered by trained eBay employees with some authority.
And you get a transcript so you can compare what you heard with what you were told.
*The phone clerks work for a subcontractor.
**Another is https://www.instagram.com/ebayforsellers/