Verification code doesn't work

We're trying to sign in to xfinity using the main user log-in name. Before allowing us to log in, it sends a verification code to the phone number associated with the account. We enter that code and then it asks us to enter the user name and password again. Then it asks to send another verification code and the whole process repeats over and over and we're never able to actually log in. Is there something we can do to fix this?