Wa Alaikum Salam. Well... When I used to live in Bahria Town, I used to buy grocery items from Chauhdry Bostan Khan road. There are some shops there, which butcher the animal in the morning in front of their shops, and then sell their meat. By afternoon, they are finished.
Then there was a shop "Rasheed Butchery" near to car chowk. I used to buy meat from there, and was satisfied.
If possible and convenient for you, you may try buying meat from that market.
Based on my experience of buying meat with PCC, Bahria Town Phase 4, its over expensive and not up to the mark. Not recommended.