Who asked you?
Did the message come through eBay messages and addressed you by your real name and not just your username ID? Then, it came from eBay and you are required to provide that information.
To be sure though, wait until 8 a.m. as that is when live agents appear in Customer Services, and at 8 a.m. there's more chance of Dublin answering, ask them to confirm they sent that message.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open for ' live agents' 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
As said, I recommend contacting CS first thing in the morning as there's more chance of Dublin answering.
@mrflibble426