@bilal_jan321: You should've flushed out the radiator and cleaned it in the first place. No reason to take you car to a mechanic every time it beeps at you (No pun intended)! Take matters in your own hands and do some dirty work.
In any case; you shouldn't have let that 'con-artist' mess-up your WHOLE cooling system. He told you a fairy tale and you fell for it, MULTIPLE times, I might add. Quite unfortunate.
As a car owner in Pakistan; you should know better, my friend.
I never take my ride to a mechanic until I know EXACTLY what's wrong with it and EXACTLY what the mechanic is supposed to do. Because otherwise; I'd get plastered with چونا .
Anyhow, the cooling system is so MESSED-UP now that I think you should take it to an authorized 3S Dealer.
Lastly, everyone make mistakes. From where do you think I learned so much about engines?! I learned from "Ustads", bro!
They call themselves 'Ustads' for a reason!
So don't sweat it. Forget the loss, there's nothing you can do about it now. Get your car 'properly' fixed and move-on.
Good Day!