Procedure to Lighten Pigmentation and Improve Complexion?

I used a home peeling kit to eliminate pigmentation which I bought in Singapore. The pigmentation came back worse, adding a dark patch along the top of my upper lip (the skin from my nose to my upper lip). I hate it, but noticed it on many women in my age group (40++). My skin is slightly tanned, I live in a tropical climate, and travel to the UK very often. What procedure should I do to achieve a beautiful natural complexion? Thank you!