I'd say it's unlikely that you will be able to get these miles back. If you were closer to the 18 month inactivity point where they expire, you would have a chance; they let you pay to reinstate the miles up to a certain date. But you're now 18 months *past* that. I wish I had better news for you. FWIW they normally alert you when your miles are close to expiring and then email you an offer to pay to reinstate them once they have expired so perhaps you are using a different email address these days.