Good afternoon Maryann,
I'm Doug, and I'm very sorry to hear of your situation. My goal is to provide you with excellent service today.
This seems like a very crucial matter for you, and your questions and issues suggest that an in-depth conversation might best suit your needs. If you are interested, for a very nominal charge of just $5 more I can offer you a personal phone conference during which there is no limitation on the number of questions you can ask of me, as opposed to continuing in this question and answer thread which is searchable and viewable by the public.
Let me know if you don't want a call and I will be happy continue here with an answer for you.
Either way, whether I call you or not, in order to give you a clear and concise answer, I will need some additional information about the circumstances, please.
1. What lies were you told by the receptionist/assistant?
2. How was the integrity of the bottom partial degraded---through grinding down by the dentist?
3. Did the dentist have an on-site lab or send the work out?
4. What did you write in the registered letter?
5. How were you threatened by the dental office after your online review?
Thanks in advance,