You could ask Kohai... She can fix this for you.
Is there any way to reactivate an old account once it has been closed?

Thank you red-lady and neo-metacrash for your ideas.
The problem, neo-metacrash, is not that I don't know how to change my username; the problem is that the username I reallly want to use is no longer available because I already registered that username once before and then closed the account.
I've submitted a support ticket and, with any luck, I'll be posting a follow-up comment on this thread as ghostmetropolis!
Earlier this year, I closed my Chess.com account because I wanted to force myself to take a much needed break from chess. At the time, I hadn't thought about the fact that my username would still be stored in the game archives and would, therefore, be unavailable for later use.
Fast-forward to today...
I've created a new account, I'm playing chess again, and life is good. There's only one problem... I miss my old name!
I know this may seem silly, but is there any way I can have my old account back? Or at least just the name?
I promise I won't close the account ever again.
Prrretty pleeeease?
Yours truly,
prisonmike (fka: ghostmetropolis)