Hi there ~Tinea versicolor
usually presents as hypopigmented rather than hyperpigmented areas on the skin especially on the nape of the neck, chest, back and the going areas and upper thighs. I believe that you have been treated for this condition for a long enough time without much benefit. I wonder if the diagnosis is right and you need to consult another dermatologist
for a second opinion
. I hope the doctor examines you after taking a good history and gives you the appropriate medications. I hope this helps.
Take care and have a lovely day!