I haven't played USTA league in 10 years. When I entered the email address associated with my account and USTA number, the computer told me I had to call the USTA!!!
We checked with our contact at USTA South Carolina, and indeed, if you've had a long hiatus from league play, you need to call them to get your account information reactivated. If you really, really hate talking to people on the phone, you can grab a different email address and create a new account. But we know you can probably handle that phone call.