face damaged

i recently developed acne( after 20years) . not sure what to use on my skin , i went to dischem pavilion. the sales assistant @ the make-up counter showed me all the products for acne. not sure what to get i went on her advice to use a clearasil face wash & a benzac gel on my face @ night. which i did. the benzac cream has now burnt my face leaving brown patches. i contacted dischem & the rep of the benzac gel has offered to pay my dermatologist consult. im now depressed because my face is damaged