Removing existing teams or channels from Microsoft Teams when no longer needed
Hello Daniel123455,
If you can still remember your credentials you can try to close the account. It will remove data on your mobile device.
To close your account:
Go to Close your account below. http://go.microsoft.com/fwlink/?LinkId=523898
If you're prompted to sign in and/or verify your account, follow the instructions.
Check that the page shows the correct Microsoft account, and then click Next.
Read the list, and click the checkboxes to acknowledge you’ve read each item.
Choose to have the re-open window set to 30 or 60 days.
In the Select a reason drop-down list, choose the reason why you're closing the account.
Click Mark account for closure.
Source: https://support.microsoft.com/home/contact?link...
Let me know if this will work for you.
Kind regards,
Jayzar