dealing with "gender critical"

[Aprilrain]

So, what is our response, what are our views, what have you done to debate, challenge, discuss, address these things? because simply cutting off the person won't help educate or shift those biased against us.

To answer this question first I need to know the situation, who is the person?
Not every person I meet is important to me, therefore not every utterance that happens to fall upon my ear is worthy of my acknowledgement let alone debate! In the situation you describe I get the feeling this person is a casual acquaintance or work colleague.
To me this person would rank very low on my "person who matters to me" list.

I did not transition to be a cause. I transitioned to save my life. My transition is 100% about me and my physical, mental and emotional well being
I personally do not have the energy, drive or inclination to try to create utopia. I have enough to worry about with my life and the people in it.
I try to let the world be. In my own life any people such as the one you describe would likely be someone I have not had to endure for at least 8 years now. They and whatever hurtful or ignorant thing they said are either a dim memory or are lost to time.

There is nothing I can say to someone who knows better. Efforts to change a persons closely held convictions are usually fruitless.