Brother I cant tell about Islamabad.
But for Honda fluids go to any Honda 1s or 2s reseller for Shell got any petrol pump or metro cash and carry.
Dont go to 3s just for fluid change.
Any oil change guy at petrol pump can do the job.
3s will charge you around 3,000 just for labour.
If you have any relative in KHi I can guide him.