They will eventually pay you. They do sometimes hold funds for up to 180 days.
Closing your account won't be instant as your recent buyers are covered by the Ebay Money Back Guarantee for up to 30 days and by their payment providers for considerably longer.
If you have sold 30 items this year, Ebay will pass your details to HMRC even if you don't give them your NI number. Why don't you want to give them your NI number?
"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)
