They may accept a birth certificate along with a recent 'official' letter for example a utilities bill, bank statement, or a letter from HMRC with your address and corresponding name on.
Use the link to speak to Customer Services:
ttps://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)