Ask HN: How to (realistically) get recourse from a large tech corporation?

I have pretty conclusive proof that a well-known software glitched and wrongfully performed an operation. In this case it affects several users monetarily.

Something is clearly in error, and we now have a conclusive paper trail about this glitch. Despite extended conversation, the company's support refuses to acknowledge the glitch or take any responsibility for it. To the point of blatantly refusing to honor their own invoices or stated agreements.

When you have a large tech corporation clearly in the wrong, with a conclusive paper trail that they are wrong, but they refuse to do anything about it? The stakes are fairly low (<$200) - what's realistically the next option? An internal email campaign? Small claims court? Document the glitch for posterity?