You rollback IMMEDIATELY or push through the issues and make a plan to attack them, agreed.
The worst projects I've ever done aren't when they change scope, it's when they change platform. Got paid 50k to undo someone else's 60k project and then make their old system work again.
110k to go exactly nowhere (Performance was better, backups worked again, business could operate).
I don't have on-going work for that business, it's currently being phoenixed as the fail project happened at the same time that the economic downturn smashed their retail business. Owner wanted to murder his accounts lady that did the project, and he still may.
The 'let's improve and expand' project became 'let's get this guy to consolidate everything so we can fire 80% of our workforce and sell two locations'.
My initial vote here was roll back, but as the initial deployment went through and they decided to buckle down and work on what they had in place it just gets to a time where the ship has sailed and you gotta float it with what you have, not what you'd like.
Let's hope 3.0 launch is f**king spectacular