I see I can blacklist, busy signal, disconnected, voicemail and forward unwanted calls.......

What is the BEST ONE to make people NOT call me again ? I seem to blacklist phone numbers but I still get calls from them...

And what is the difference between the ACTION and APPLY blue button, shown AFTER I make my selection

Can I get a list of all the numbers I have BLACKLISTED as I can see if one I want on it is there ?

Thanks in advance...