Recently active topics in Twitter tagged with deny

Is there any way to prevent people from adding me to their follow list? I am constantly denying follow requests from people I don't know who want me to "know the grace of God" or buy their product. No. No, thank you.

I have a protected account. Someone sent me a follower request. I blocked this user and also denied their request. This was yesterday.

Today, I sit down and view Twitter, and somehow the blocked user has sent me a new, second follower request. I have confirmed they are currently blocked because the link at the bottom of their page says "unblock." Why can a previously blocked user send me a new follower request?

When I click on the NEW FOLLOER REQUESTS, What happens if I ht DENY? - why do I have to accept or deny a person following me?

What happens when I click "Deny" when someone wants to follow me? Are they told explicitly that I denied them? Are they blocked forever from contacting me again? My tweets are private.