And Obama promised that, "if you like your healthcare plan you can keep it". Try suing him on that statement.
*cough cough* sovereign immunity COMPLETELY DIFFERENT AND UNRELATED SITUATION *cough cough*
Just because there was a promise does not mean that entity will keep the promise. If a corporation knows they can make money with a false promise, or by not keeping a promise then they will do just that.
And this is called fraud, which carries both civil and criminal penalties. There's a reason only criminals do this...