What Is The Remedy For Scars Caused By Pimples?

i m a girl and my age is 21.. i m suffering from acne from last 6 years... from last 1.5 years the condition was much better,i occassionally had 2 or 3 pimples,but they always got better after some days.my pimples always leave dark scars ... and from last 1.5 month i have again developed this problem.. i m having 6 big sized pimples on my right cheek.. i used turmeric and lemon juice paste on them but it was of no use.. kindly help me in this regard as i m very depressed due to this problem