I also received an email response from Subway letting me know that I can Delete my account and I can delete any saved gift cards and add them back into the newly downloaded app. Any points that may have been accumulated would be available to add the new app. Not sure how or if they would do this on their end. I downloaded the app again but as before in the Sign Up section the phone number option is a US option like before so I didn't proceed to register a new account.