That really sounds disappointing. Did you analyze your voice in terms of pitch range, average pitch and such? Can you quanitfy your changes in terms of Hz. Maybe you can post a pre-op (unmodified "male/chest" voice, feminized voice) and post op (chest voice, feminized voice) recording, so we can analyze them and see if we can find some things.
What were your expectations exactly - how high pitched did you want to sound?
I think, Aphaea is right in that the surgery will not help with some other things that need to be trained by voice training - and I mean not only the ones that Dr Kim tells you to do. May I ask, if you did voice training before or how long you have been using your feminized voice before surgery?
I hope we can help you with that. don't feel so bad about it right now - I am sure there is something that can be done, still. Did Dr Kim do pr-op recordings? You can ask him to send them to you and then repeat them now and we can compare. If it did really not give much improvement in pitch, maybe it will pay off to contact Yesons again and ask them how to go about this, if there is improvement to be expected or what could have happened. Have you visited a local ENT or Phoniatrist to take a look at the surgery site, maybe take endoscopic videos or photos? It could help to see if the healing is good, if all the sutures are still intact.
Good luck.