Advice?

[dressedallinfur.livejournal.com]

Hello A_B community, I do apologize if this isn't the place to ask, this is my first time posting here, but
I was wondering if you could give me some advice.
Recently I had put up a notice on my etsy shop that I couldn't take any more commissions because I am starting school. A day later another etsy user bought a commission from me without contacting me first. I have sent them a message five days ago and two days ago I had sent them another and they haven't contacted me back. Also, they didn't provide any information on what they wanted in the notes section too. How long should I wait before I should contact them again? Should I cancel it and refund them if they do not contact me at all?