Pakistan controlled?
That was, is, and will always remain Indian territory! Period.
Payback like what? Your much talked about super SSG tried their damnedest to wrest the Soltoro Ridge West of Siachen from Indian troops in the 80s and early 90s but had to face the ignominy of being thrown out unceremoniously each time.
Even Gen Mush who led several SSG attacks in Siachen to dislodge Indian troops had to finally give up with a lot of egg on his face after unacceptable casualties suffered by his SSG!
He was so pissed, he tried to take revenge by launching his disastrous Kargil operation and from there capture Siachen. Again he had to beat a hasty retreat after Indian troops recaptured all posts and destroyed the main logistics base at Mantho Dhalo thereby starving Pak troops of supplies including food, water ammo etc.
So what form of 'payback' are you waiting for?