Cannot complete thesis and blocked to go non-thesis. What other avenues towards a degree exist?
Where I am, a non-thesis option requires only the approval of the department (meaning the department chair) and the graduate school. A "non-thesis advisor" is considered an oxymoron. At best, graduate students in this position are advised by either the Department Chair or the Chair of the Graduate Programs for the Department.

Put together a Program of Study (PoS) based on the Graduate Catalogue for your university and department / program. Your university probably has an on-line form to complete and submit. Confirm that you have met all of the administrative requirements. Then ...


Talk to the Department Chair.
Talk to the Dean of the Graduate School.


When you meet all of the PoS requirements for the degree, and with their approvals and signatures, you should be done.