I paid the payment for the entire apartment for 4 days but host hasnt confirmed it yet. My application is pending and expires in 6 hours. If it expires do i get my payment back immediately?
If you have used Instant Book then you have paid immediately and your booking is confirmed. You will have received an email tell you that it is booked and confirmed.
Sounds to me like you have made a booking request, which they host has yet to answer - in this case no money has been taken from your card as you do not have a confirmed booking. The host has 24 hours within which to respond to you.