My acne scars have hardened like melasma. What kind of pigmentation care is most effective?

The pimples and blemishes that used to appear intermittently on my face failed to heal properly. They turned from red to brown and intermingled with existing light melasma, leaving my entire cheek looking messy and speckled. It seems my skin's turnover cycle is completely messed up; even after months, they haven't faded or fallen off on their own and have settled into my skin like tattoos. I've tried applying whitening patches said to be good for melanin care, and even tried using a galvanic device at home to absorb essence daily, but the brown marks deposited deep within my skin haven't moved an inch. Well, I suppose that's to be expected... So, I am currently looking for a professional procedure that helps regenerate from the basal layer of the skin to gradually push out the pigmentation and even out my complexion for a clearer look. I would be grateful for any advice on dermatological treatments or skincare routines that have effectively acted as "mark erasers"—clearing away the brown discoloration and clustered melasma spots that remain after the redness faded, just like mine.