Unfortunately, you won't get any sense out of some people on this issue. There are basically two types of people in their mind when it comes to discussing LGBT: pro-LGBT people who completely agree with them and right-wing, Nazi, White Supremacists who are lying because they hate trans people, with nothing in-between.
Their minds cannot allow them to accept that any rational normal person might have a valid concern on any of this.
Even if you put together a solid argument, with evidence to back it up, once they see they are beat they will start saying that you're being aggressive and trolling. Then they pick up their toys and run home because they don't want to play anymore.
It's all simply too ideological and the cognitive dissonance kicks in.