2 Answers

Since there are many different types of phones and phone services out there now, I would suggest that you contact your phone service provider that you have and ask them how to program your phone to block unwanted calls.

This applys oto all cell fones.

Log into your Google Voice, ( If you dont have a Google Voice account) you can sign up. its free. Then you will have the option of send them to directly to voice, treating all their calls as spam or blocking them entirely.

 Log into your Google Voice  account.

Find the call you want to block (or the voicemail, that resulted from it)

Select the Checkbox, next to call or voicemail,

Click (the more link)underneath the call,

Select, Block caller.

This is best option, assuming your OK with transferring your cell phone number to Google voice.