You raise many issues.
If the attorney has money you have paid that he has not yet earned, he must return that money to you immediately upon your demand. If he fails to do so, you can go the California State Bar and make a complaint.
If you paid him money that he claims he has earned, but you dispute that, you can either proceed by arbitration or litigation to prove that he did not earn the money he claims he earned. It is likely not a bar disciplinable offense, but a fee dispute.
His failure to do work when he said he would could be a Bar discipline offense.
As to an agreement to remove negative reviews, and threats of legal action if you do not remove those reviews, the issue will be did you agree to remove the reviews in exchange for something of value, and did you get that value. If not, his only way to sue you for the negative reviews is if you made false statements of fact in the reviews. Generally there is no claim of defamation (slander or libel) for statements of opinion, and reviews are often just that - opinions. However, you should have some concern if in your frustration with this attorney you made false statements of fact in a public venue.
Good luck to you.
This answer should not be construed to create any attorney-client relationship. Such a relationship can be formed only through the mutual execution of an attorney-client agreement. The answer given is based on the extremely limited facts provided and the proper course of action might change significantly with the introduction of other facts. All who read this answer should not rely on the answer to govern their conduct. Please seek the advice of competent counsel after disclosing all facts to that attorney. This answer is intended for California residents only. The answering party is only licensed to practice in the State of California.