Not letting me to create username since from yesterday

I have signed up and made payment yesterday. After making payment, I am not able create the username, not letting me to create username, if possible create my usernameas sameera123

Trying from long time and finally below is the message I got.

Your access to this site has been temporarily limited by the site owner

Your access to this service has been temporarily limited. Please try again in a few minutes. (HTTP response code 503)

If you think you have been blocked in error, contact the owner of this site for assistance.

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Block Technical Data

Block Reason: You have been temporarily locked out of this system. This means that you will not be able to log in for a while.
Time: Tue, 10 Nov 2020 2:55:43 GMT

Hi @Sameera, Can you please tell us your available time from MON - FRI 9 AM - 5PM IST for a short zoom call?