Three months to issue the Notice to Owner is pushing it a bit but is probably not a winner at adjudication, although needs mentioning if you get that far. The legal limit is 6 months.
Basically, at Notice to Owner stage, the discount is lost, although they may re-offer it if they refuse your reps, but if they don't, it is a no-brainer to take them all the way to adjudication, because the penalty remains the same, and there are no additional costs.
As our esteemed administrator is on your case, I'll defer to him for your next actions