Lol the demands from this guy never end even after agreeing to refund him, I'm not going to call your bank and cancel your pending payment, thats up to you. I don't even think I could stop it even if I wanted to, and I looked for an option on dwolla but I don't see one. If they have that option let me know exactly where to go, otherwise you need to call your bank.
As for the request to receive a refund in dwolla instead of BTC, that is fine by me.