Old number showing under "reachable at"

So I turned off iMessages and FaceTime on my old phone when I changed carrier and phone numbers. I also logged out of my Apple ID on that old phone. That device no longer appears under my devices, and on Messages/FaceTime settings on my new phone the old number doesn't appear, which is good. However, when I go to Settings>Apple ID>Name, Phone Numbers, Email...The old phone number still appears there under Reachable At. The info bubble says I need to deregister it to remove the number.

Since I already turned off Messages and FaceTime in the settings of the old phone, and that apparently didn't work to deregister the number from my Apple ID, I also tried to have a code sent from the deregister online option but the code isn't going to my new phone number nor my email (old phone number is no longer in service)...so how do I deregister the old number if the code isn't going to my new phone or email?