It is possible to powder over chrome, but you have to still follow certain steps and it's normally only done w/ translucent colors. Any shade of black (or basoically any other color other than a translucent) the top chrome layer should be Sandblasted, treated w/ Acetone or Denatured Alcohol, gassed out, shot withh powder & then cured properly per the powder manufactuer specs. No way should your stuff be flaking as you describe.....Request a refund .....with what you describe, I don't know that I'd trust him for a re-do.....Good Luck
**** in the attached the floor board pans & kick stand are in Satin. The kickstand bracket is gloss. The dash you can see the center is Chrome.... the remainder has been sandblasted.....this is how a part should look like before powder hits it......