Thanks for all the replies.
Mine is a PI car so getting a new set of wipers is tough as
there is no authorised dealers doing it.
All trials & errors were done, yet same problem arise. Does
sending it to the Car Waxing company helps if the problem is with
the windscreen?
Wiper blades are not car-specific, ie the wiper is not specially
or specifically designed for that car only. Wiper blades are
categorised by their length, as long as you got the length, you can
buy the rubber blades at most accesories shops and replace them
yourself.
Sending the car waxing will not make any difference because...
they will not wax the windscreen anyway. It's much cheaper
attempting to clean your windscreen yourself using a suitable glass
cleaner.