SCAMMERS

There are a couple of things you can do to block incoming calls.

First, use Voice Tools to block spam callers.  https://voicetools.cox.com/

Voice Tools > Settings > Spam Blocker: Customize

The phone won't ring for blocked numbers, but they will appear in Call History.

Second, use phone codes to block up to 25 selected numbers.  

• When you hear a dial tone, enter *60
• Press 2 to add phone numbers to be blocked.
• Enter the number to be blocked and press # or just press # to block the last number.

I don't think you can block individual outgoing calls. Just curious, but why would you want to? Does the scammer ask your mom to call back?

WiderMouthOpen  is correct.  You can't block an outgoing call.  You can only block your name and phone number from being displayed.  Using Caller ID Per Call Blocking (cox.com)