I'm also sorry about the snotty attitude the store/teacher dished out.
My LQS is a Bernina dealer. However, they do offer a beginners class titled "Welcome to Your Machine" which is open to anyone with any brand machine. What they do ask is that you've at least turned the machine on so that you know it works before showing up at the class. There is a modest fee to cover the teacher's time. They also offer a series of classes for new Bernina owners specific to the machine that they've purchased - those are restricted to the particular machines - and I have no issue with that policy.
I've taken several of the quilting classes through the store now, and been very impressed with their customer service. When I walked in with my "new to me" - "purchased of eBay" vintage Bernina, several people got excited about seeing one of the classic machines and told me stories about how this was the machine she bought when she started sewing in the 70's. I'm glad to give my "new to me" machines a new home.
Cheers, K