Prepaid $10,000 for 40 lessons, got 13, then was refused service with no refund

I prepaid K9-INDIGO for a 40-lesson private training program for my Golden Retriever in June 2021. We completed 13 lessons. The trainer confirmed lesson 15 for Oct 30, 2021, then cancelled it the night before with "No longer available" and declined to reschedule. My emails on Nov 21 and Nov 29 asking whether they would continue or refund went unanswered. In December 2021 and January 2022 the business wrote that I was "terminated" from the program and that it was refusing service. It kept the payment for the 27 lessons it never gave. I asked for a pro-rated refund and have not received one. If you buy a large prepaid package, get the refund terms in writing first.