From the sign in page where you can enter your password, click in "Need help signing in?" and select "reset your password". At the bottom of the next screen there should be a link to contact eBay which should offer a couple of options that may include a call back option (which may not work outside the US or if you cannot answer your number on file) and a chat option. Outside the US there may be alternative options.
If that does not work, try contacting eBay via social media.
https://twitter.com/askebay
https://www.facebook.com/eBay/