Be cautious when you go to exchange money at the currency exchange offices .

You could get cheated if they count out your money behind the desk or count too quickly for you to keep up. However they do it you will be out of pocket.

Always ask before changing your money how much you will get, don't pay tax or commission. When they give you the money, count it again in front of them, do not leave until you get the amount you should have. 

Stand up to them and once your point is made and you get an honest transaction, go back to the same office and you shouldn't be cheated again.