So I added 12$ to my prepay then I bid on a domain. Won the auction and now I can't buy with the money from prepay because it still says processing so I have to pay another 12$ to purchase the site because I got on email that said if I don't pay in 24 hours the domain will be taken from me. That is not really fair. :)
Your prepay order is probably processing because there is a verification that needs to be completed. Once you do that, the money will be added to your Dynadot account balance.