Mohtaram Tarar Sahib,
It is quite alarming for me to learn bout that type of horrible experience which you have gone through. Fortunately it has not happened to me in about 40 years since 1974 when I started using Pakistan Post. It all depends what service one uses. I always go for registered post. Once my family sent me a packet through 'Priority Mail' from USA and it took around 40 days to reach me. Another time, it took it 4 months to reach me. Now, had the sender looked into his options he could so easily have sent it through 'International First Class Mail' and it would have taken it only 10 days to reach me. That would have cost the sender another $10 per packet to send it through 'First Class International Mail.' It all depends what service one opts for.
In 40 years Pakistan Post has never gone wrong for me. I have used it for sending extremely important documents and not a single time it has gone wrong because I've picked the right option for the service.
In my case the sender chose an $ 11 service (Priority Mail) and the time the packet took to reach me in Pakistan was once 40 days and the second time 4 months. Had he chosen a $ 25 service (International First Class Mail), it would have taken the packet only 10 days to reach me. As the old saying goes, you get what you pay for.
Regards.