Hero Motocorp — Parts quality issue

After purchase my bike model splendor+ special edition (OD02BE8734) but sorry to say that after 4 th service my all nickelling parts are rusted . After complaint & visited to dealer point regarding 5 th servicing they replace my back shockobserver colour model in place steel nickel & other parts like ( silencer cover, leg guard etc)avoiding to replace .As a customer I am expecting this type of inferior quality
Kindly resolved the above issue as early as possible & waiting for your valuable reply in fever of me.
Regards
Basanta Mishra