This was who we originally had selected for ours, which was 2 years ago. He responded, and was available and everything was fine and dandy. Then when we arrived at the ceremony, it was someone else (I don't remember his name). Apparently Rev. Day had some health problems, and was unable to make it. Our coordinator claimed she had notified me, but she never did (one of many reasons I wasn't happy with her).
Anyway, I have heard of people using Rev. Day since our wedding, but it is possible he is having health problems again and that is why he is not answering you. I would contact your coordinator and ask if she knows why he may not be responding.