Good evening, sadrapida!
Welcome to T-Mobile and to our Support Community! MyT-Mobile is a helpful tool and we really want to get this working for you. It's odd that the verification is sending you the same code and still isn't working. Our Tech Support team needs to get a trouble ticket filed for you so our web Engineers can figure out why this is happening. You can either dial 611 or you can work with T-Force (our social media Customer Care team) via Facebook or Twitter.
Please give that a shot and let us know if that does the trick!
Same thing is happenning to me, so can't access the App or Digits app.