Here are instructions that will help you out!
Delete your Teams free organization – Office Support
I called them, but they could not help me to delete my free account on the phone. They sid there was no way they could help me.
Thanks for the feedback. Keep the suggestions coming!
9 votesPernille commented
I really need to change my display name in order to use Teams. Today, my display name is somehow spelled wrong, and in such a way that it means something nasty. As it is today, me and my business, organization and friends, are not able to use Teams.
I would like to use Teams, but, when I va\cannot change my display name, it is, unfortuneatly not possible.
I hope there will be a possibility in the future to change the display name, or that there will be other alternatives to Teams.