I can imagine scenarios where a full refund would be make sense, but refund isn’t really appropriate when we’re talking about small changes in schedule, especially when everyone agreed such changes were possible.
Yeah, that's your prerogative. Personally, I'd eat some bad press by just making it a policy to always have opt-in changes across the board, or offer dissatisfied students refunds. And saying "everyone agreed such changes were possible" when you're essentially talking about the fine text of a contract only one side has the opportunity to define the terms of seems questionable. We aren't talking about two sides in a negotiation coming to a meeting of the minds. You created a contract with those terms, on top of an already questionably structured ISA. You can change the contract to make it more explicitly favorable to your students.
See my other thread here about how by not being a progressively structured ISA, you can cause the most harm to students who get the least out of your 'school.' Not to mention your securitizing of ISAs removes the argument for your model that you align your business with the success of your students.
But frankly, if the only thing you took out of this post is that the ISA structure is poor, without considering how you have all the power to set and enforce terms in your contract, I don't think I have much else I can say to try and help you. I think there are a lot of ways you can improve Lambda School to make it better for the people attending. And they don't involve deleting Reddit threads of criticism.
"Small" is really exaggerating the changes. Schedule is just a small part of it. But while we're talking about schedule, many parents that are students at Lambda School struggled hard with the increase of meetings after the changes were implemented.