Can it be that the service expired, and you forgot to renew it? No matter what, we other users are not in the position to help you. You better contact support.
Are you still experiencing issues? Standard DNS is showing no incidents for the 13th, and is properly running at present. You can find details to its status at https://www.dynstatus.com/ under "domain services"
As Rotblitz said, it could be a subscription expiration or your renewal failed. In either case if you have not contacted support already, please reach out to them for assistance with your account subscriptions. If you have, please feel free to share your ticket number with me and I can follow up with support on your behalf.
Oracle + Dyn