How can I cure skin burn/darkness on my neck? It was caused by me using a cream containing hydroquinone for 1 year. (photos)

I used hydroquinone containing cream in 2013-14 to get rid of tan and got good results then I kept using it for almost a year and stopped using it. Since then my neck started getting darker and now it is too dark. I went to laser treatment center but they said they don’t wanna give treatment because my skin was damaged by hydroquinone. So I used some other creams which didn’t work at all. I’m not sure it happened because of hydroquinone or something else. Please give me best suggestion. Thanks