Assuming no pay increase, titles are free. If you're already managing the tech teams, then you should be able to get the VP Eng title with little problem. It's a win-win situation for them, too: you're happier with the nicer title, it costs them nothing, and it looks better on your resume when you choose to leave.
If you want VP of Engineering and a pay raise, that's another story altogether... Sounds like you fought the pay battle already. I'd push for a better title.
The few comments posted before this one are valid and good advice. Stick it out, and keep pushing for the things you want. Good luck!