This happens when:
1) You fall for too good to be true trap.
OR
2) you dont do your research work on who you are dealing with.
Financing / leasing in pakistan by the companies other than Banking institutions or Non banking finance institutions is illegal.
And
if it is a straight up installment scene without any financing or interest element then one should'nt be stupid to be oblivious of the logic that why would someone tie up their money for providing cars on installment to someone else. This is straight up 2+2.
In such scams, people giving them money are equally to be blamed.