If the party refuses to listen, your advice is???
Apparently - to toe the party line.
Keep trying and work harder. More conservatives need to realize it all starts at the local level. Yakking on the internet is fun and a useful way to network, but perhaps you'd be surprised at how much more can be done at the local, city, county, district, etc, level. That's how conservatives influence and takeover the GOP. And we are doing just that. Tea Party folks, movement conservatives, etc, have made unbelievable strides at the local and state level. It didn't work out at the national level this time around, but if we keep pushing from the bottom up we will be more successful going forward.
Screaming at that establishment that you'll refuse to vote for Republican nominee's only makes them ignore you. If you announce your not part of their party, then why should they pay any attention to you? Better to just take over from within.