Blocking an unknown number/unavailable number

Hello.  

I'm hoping someone can help me an issue I'm having with my wireless home phone.  I know how to block phone callers and block private calls, so that is not an issue.   However, how do I block that showed up on my caller id "Wireless Caller", "Unavailable" and the number is "Unknown Number".  I've gone to my account only to see that I can only block "Private Caller" and/or numbers that I wanted to block.  Is there a way that I can block this particular name "Wireless Caller", "Unavailable" with an "Unknown number".  Very frustrating.  

I appreciate all suggestions.  Thank you so much!!