I have Cox Cable and when unwanted calls come to my home, after they hang up, hit the dial tone, hit the star key and 60.  A recorded voice will come on and say, "Your screen service is now on (something like that)".  Then it will say, "To add the last caller....hit #01#.  Some numbers cannot be blocked, but most can.  Eventually you may get so many blocked numbers (like we do), that you have to eliminate some in order to make room for current jerks who call.  Usually by the time the list is full, the other guys have given up on you!  Hope this helps.

I ported my landline to a $10 prepaid cell phone, then ported it to a Google Voice number. No more landline! Saves me money each month, and all calls to the old landline number now go to my cell. I can block whoever I want to now. Google will send known telemarketers to voicemail and not let them ring through. They show up in the spam folder, and you can block them if you want. It's funny to block a telemarketer, then see them angrily call me 15 times the next day. All they get is... beep-beep-beep, this number is no longer in service. They fume, and I laugh my a** off!

the number:602-354-9177 is answered by a machine stating it's a call by the Fraternal Order of Police looking for funds to help families of officers killed or injured on the job.
I left a message to remove me from the call list.

How do you block numbers?

as soon as I answered they hung up
Nuisance!!
I blocked the number from calling again

Same. Called, no message

Received call on landline.  No message left.