Each bounding box should be specified as a pair of longitude and latitude pairs, with the southwest corner of the bounding box coming first.
Your co-ordinates of 71.69,32.01,70.69,33.01
give this (which only seems to be a small part of Pakistan, might want to have a larger box):
So I think you box isn't being formed correctly because you're not giving the bottom left (South West) corner of it first. In order to give the box co-ordinates correctly you need to have them in the format bottom-left-longitude, bottom-left-latitude, top-right-longitude, top-right-latitude
.
Try using 70.7,32.1,71.7,33.1
(I've rounded the figures) instead which will give you the same area you suggested originally:
In order to get the whole of Pakistan try using: 62.9,25.2,73.3,35.2
which give you the area:
I use this website in order to get the latitude/longitude values. Note that the website gives you latitude, longitude but Twitter wants longitude, latitude. Remember to swap them around!