They have been doing this for any account registered from a VPN or Tor. However, you can simply appeal the block and tell them you haven't tweeted and not broken any rules. They will send you an automated mail, offering to validate your phone number, or reply to the mail if your problem is not solved. Just reply to the mail. Unfortunately, processing the request takes anywhere between 10 minutes and 2 weeks; usually…
I signed up using a Tutanota e-mail. Every time I got a verification code and then entered it into twitter I got an "Oops, something went wrong." message. After spending many hours in vain trying to find Twitter's e-mail support, I gave up and initiated a "Trouble logging into my account" help procedure. However, that ultimately failed since surprise! Twitter couldn't find any history under that account name.