How is your wrong side? It looks like it could be interesting looking, even if different. Can you consider removing the facing and using a binding on that edge, or even just a hem with a mitered corner?
If that wouldn't be acceptable, at least have you tried to understitch the back of the collar, so the facing lies properly under there? Did you just tack the facing to the shoulder seam at its end, or did you stitch in the ditch the whole length on the shoulder seam part that overlaps it? I find that often does more to tame a wayward facing. If the back facing flips out, you might consider stiching the collar and facing together along the back neck virtual seam, it wouldn't show under the collar (you can baste it first to see whether it helps and be sure it doesn't show)
I'm afraid most commercial patterns have inadequately wide facings, they just try to save you fabric no matter what. Ironically, it was Sandra Betzina who taught me that, and pointed out that good RTW has back facings at least 6" deep. I'm now systematically adding to get that, and haven't had a back facing flip out in decades. I also find that adding at least an inch or two to front facings does the same trick for the front.
Poor Sandra, remember the time when she had to recall thousands of patterns because she realized that someone at Vogue had re-drawn her good crotch curve on some pants, to replace it with the lousy one that makes us buy her patterns instead?? Wish they'd leave her stuff alone..10/6/10 4:55 AM