[antonye]

You probably "logged in" to a fake ebay page which captured your username and password. The crooks then use this to do exactly as you say - change your details (to stop you getting back in) and list lots of stuff to scam people with.

Never *ever* use any links in emails or on websites to log into ebay, or any other website for that matter.

*Always* type the website address directly into the browser, and do it from there.