So presumably you have a contract with an independent architect. As already mentioned, only a lawyer can really help you here and, above all, move things forward. Just to set expectations: the architect "owes" you the agreed service (e.g. planning for performance phases 1-3). If he has basically delivered that, you owe him his fee for it. The fact that the architect did poor work, did not reach an agreement with you, or was unfriendly is quite irrelevant for his payment. Proving that he provided poor quality work will be difficult to impossible. —> therefore, a settlement could be the most sensible way.