Chafed Skin Hyperpigmentation? (photo)

Hi. I Chafed my ankles from wearing boots a year ago, and now I have dark lines on both my ankles. Sought treatment, and was prescribed hydroquinone. Kept applying hydroquinone for months until I noticed that the lines got even darker than the initial problem, so I stopped. Went back to my doctor to try the nd:yag laser on one ankle. Already did two laser treatments in 3months with continued use of hydroquinone, but still... nothing is happening!!!! What are my options at this point?