What is the most effective way in removing pimple and blackhead blemishes?

I've had this marks for almost three years already and still I can't find the solution for it. Before I had these marks, I used a product called panoxyl which dries up pimple. I think it irritated and burned my pimple causing it to have marks. Since then, I cant remove these marks at all. and worse, it just kips on multiplying on other parts of my face. I tried diamond peeling and other products, but still, it didn't help at all. pls help. thanks