Accidentally claimed a domain – need to delete urgently

I followed a link to a vacant WordPress.org domain (I presume the hosting had expired or something!) at the same time as I was attempting to set up a WordPress.org site, and now I appear to own that domain. I do not want this domain – it is someone else’s website, and is linked from their multiple company profiles. There is no way for me to delete this site in the dashboard and WordPress don’t think that customers who can’t pay should have access to telephone support. I’m at my wits’ end here – I don’t want this domain, and changing the name of the website in the dashboard settings hasn’t worked; it just means that you get redirected to my empty site when you type in the previous URL.

To make matters worse, I can no longer log in to the account which is now linked to that domain, as the password provided to me does not work and the email used to make that account is not showing as registered (so I can’t log in as I can’t get a new password emailed to me). I’ve had to make a new account just to post this support question.

This means that I unintentionally own someone else’s website and have no way AT ALL of deleting it. I am incredibly unhappy about this, for obvious reasons.

Any assistance would be greatly appreciated.