I suggest you change your wording. Saying there's no such product makes me think I either entered in some wrong information and try again.. and again... or makes me think there's a mistake in your system.
Your best bet would be having an email opt-in pop up letting me know it's not currently a product you're buying but I can be notified when you are. (like you just did)
Your best bet would be having an email opt-in pop up letting me know it's not currently a product you're buying but I can be notified when you are. (like you just did)