Now I have to pay, but I want a free account. How do I undo this?
bjergkoebinggrandprixdk.wordpress.com is currently using the Free plan — you can continue to use this plan for as long as you like.
Certain features like custom domains are only available with paid plans, which is why you may be seeing an upgrade message. If you would like me to double check, please create a screenshot of the message you are seeing: