What you can do very much depends on what you have been told in the email restricting your account.
Does it state this is a permanent restriction?
Generally, if it is a permanent restriction, Customer Service agents will not enter into a discussion with you.
It looks as if you have had this account for a long time but have never sold any items.
Have you ever sold anything on Ebay, on this account or a different one?
Have you previously been banned from selling?
Have you registered for managed payments?
"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)