[yamtaddle]

MS isn't even giving them an idea of what sort of thing they think is going on. Completely ghosting someone is way beyond not disclosing fraud detection techniques.

"We're using our enormous market power to wreck your company and won't even tell you roughly the kind of thing we think is wrong" is so unacceptable it ought to draw an application of some kind of corporate death-penalty, if it's a pattern of behavior and not just a rare accident that goes against official policy. Certainly it's, all on its own, a strong argument that there shouldn't be companies this powerful in the first place.