If students complain about availability, but never show up despite everything you did, then that's their problem. What people say and do is, unfortunately, not the same.
And I'm sorry to hear about the strange incentives for not being able to report to the department about cheating.
Initially when I started the app, I was very anti-teacher. But as I learnt more and talked to more teachers, I realized, man teachers also have their fair share of indignations from the system.