You have had a recent transaction and an item a buyer never received, has this been resolved? Has a refund been requested and made? Your account will not close until this refund has been completed.
Do you need help with a refund? Come back here and we can advise you.
Then, go to Site Preferences >> Account Preferences>> Close Account.
With a recent transaction, your account will not fully close until 6 months has lapsed.
@wah2522