How to get owners to actually respond during booking requests?

I've gotten a lot of requests from people. Sometimes I will reply with questions and they never answer me. And then that request sits there until I decide to archive it. Which makes me look booked on those days until I archive. I had someone come out for a meet and greet. We all seemed to get along great, and the dog was wonderful. They said they would confirm the booking once they got home. It's been 4 days and they still haven't confirmed the booked (I had to request it again because it expired). And they won't reply to me. This caused me to loose out on another customer who requested that I sit during those same days.

I get the impression that customers can request bookings with as many sitters as they want, until they find someone they like. And then have no obligation to inform the other people or cancel the requests. Is there anyway to change this? Make it so that once a owner has booked, then all the other requests get archived?

Has anyone else experienced these issues?