If they're online at the same time as you are, then just use the Q and A section to post a message.
You would have to create a new user name that has not yet been blocked by the person you are trying to message.
Make a new account
You can ask a question Adkins WHY they blocked you? You will get a response!
Quit stalking man.
I was just kidding.
Can you post a comment on one of their stories? I don't know. Just a thought. Ask someone else to relay the message maybe.