Can anyone tell me how to get the ACU collar to behave PERMANENTLY?

Extra stitches along the seams for stiffness, that just might work!

I tried the strong command voice, but it just ignored me...

What about the knife hand?

Well, then perhaps some sort of dickie would do the trick.

When you fold it down to where you want it, press it with an iron to get the permanent crease that you are looking for. Don't zip it all the way up, about where the top-to-mid way of the hook-and-pile fastner is where you want to go. Hope that helps. It does for me.

the collar itself usually isn't the problem. the problem stems from either the intended creast passing along the velcro patch, or mainly from the strip of cloth that lays under the zipper being jacked up in the wash, if you can get that cloth to lay flat the collar will follow suit. also as SSG Purham suggests, don't zip it up all the way, zip it up just to the bottom of the velcro patch.

One should also consider the crack build quality and terrible stitching/sizing of fabric. These uniforms look like they were sewn together by blind children.