Hello! It seems like you are experiencing difficulties creating a new Gmail account using the same phone number after deleting your dummy Gmail account. This issue could be due to Google's account creation policies to prevent abuse and ensure security.
When you repeatedly try to create new accounts with the same phone number in a short period, Google's system may flag it as suspicious activity or as potentially violating their terms of service. This is why you may have received the message "used too many times" when attempting to register a new account.
To create a new Gmail account successfully with the same phone number, you may need to wait for some time before attempting again. Google's system usually resets after a period, allowing you to try again without triggering the same error message.
It's important to note that creating multiple accounts with the same phone number can sometimes be against Google's policies, so it's essential to use accounts responsibly and within the guidelines set by the service provider.
If you continue to encounter issues, you may consider reaching out to Google's support for further assistance or clarification on their account creation policies.