I am so sorry to hear that after all that you've been through you are unhappy with the result of the Restorations you received.

Before you go running around searching for a new dentist, you should speak to your current one and ask about the yellowing. From your description it is impossible to tell whether the yellowing is just a stain that was put into the nearest to make them look real, hygiene stain which could be cleaned off readily, or just the cement line that stained yellow very quickly. If you can't get a resolution with your current dentist, go to the specialist in this area and find a prosthodontist who would be happy to look at your work and evaluate it. there are plenty of prosthodontists in New York, just look online.