You did very well. I can tell you from my experience, you can't teach the elders anything.
As you did in the beginning, you said they can only visit you if they write their points and only with one elder. They blatantly disregarded your wishes.
If I were you, I'd tell them if they want to meet again.
"Thank you elder xx for your concern. My personal faith and relationship to Jehovah and Jesus are very dear to me and PERSONAL, which I won't discuss with you. I will let you know if I feel the need to talk to you about it."