Suspicious sales involving i phones that you have no knowledge of, sounds like your account has been hacked, and you need to take actions asap.
Lines to eBay Customer Services are currently closed, but reopen at 8 a.m. contact them first thing as there's also more chance of Dublin answering. They have access to your account and can close it immediately to investigate.
Contact your bank when it opens too.
Change passwords on all accounts you own, especially your email account.
Report your hacked account here:
https://www.ebay.co.uk/help/account/protecting-account/securing-account?id=4196&st=2&pos=1&query=Sec....
The easiest and quickest way to contact Customer Services is through this link, for a Call Back .
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
On weekdays lines open between 8 a.m. and 10 p.m. - 6 p.m.
Weekends lines open between 9 a.m. to 6p.m.
@missmarmite666