Car windshield blurred, light is dispersed at night

Hello,

I have taken my car to garage and before that my windshield was totally anti glare at night driving also. The guy had applied wax polish in my car and cleaned the car with a dirty wet cloth, after that the whole windshield has whiteness seen all over.
I tried to wash it with shampoo but it doesn't work. At night any coming light is dispersed so badly that I couldn't see any thing.
Could you please suggest how to resolve this problem?

Thanks & Best Regards,
Yogesh