I would encourage affected customers to go to small claims court. You’ll probably get a default judgment. Small claims court was created for just this type of issue.
But you most likely signed a binding arbitration clause in the TOS
But they’ve got you. Nobody uses Microsoft office turdware unless they’re locked in and have to.
You lose access to it. You’re cooked.
In Australia, the ACCC. They made Apple change their warranties.
IMO it would be better if there was a general mechanism to prevent profiting from corrupt business practices. For example, a court could determine how much money Microsoft made by selling perpetual licenses that turned out to be a lie, add interest, add a 50% penalty, and require Microsoft to pay all of that into a trust to be collected by any customers harmed.
The point would not be so much to help the customers but to cause the actual cost to Microsoft to be sufficiently high as to disincentivize corrupt behavior.