Suggest Treatment For Acne And Blemishes On Skin

Hi, I am a 24 year old East Indian female,I have a dark brown complexion and my skin is very oily and sensitive. Currently I am suffering from post acne marks on my face, that is......the flat brown and black spots I have used a couple bleaching creams but they do not seem to be working. These marks have existed over 6 months and they have not shown any signs of fading, I would appreciate any feedback on this matter. Thank you in advance!