Why I cannot cash out the amount in the account

Sorry, you need to contact Apple iTunes support. The community forums do not have access to your personal or financial information.

iTunes - Official Apple Support

See the section entitled, “If you have Apple Account balance that you can't use” …

… in this article:

Check your Apple Account balance - Apple Support



Also be advised that you generally can NOT “cash out” your AppleID funds (i.e. have them refunded to you)

You can only EXCHANGE them for Apple goods and services.