What does the email telling you that your account is restricted actually say?
You haven't used your account for a long time, so they may need to verify the account has not been hacked. Did they ask for ID?
Or, it may be that you have never signed up for managed payments or added a bank account.
Put 'getting paid' as the search term into 'Help & contact' top left of your Ebay page, or details here:
https://www.ebay.co.uk/help/selling/fees-credits-invoices/setting-changing-payment-method/updating-c...
"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)
