So, what did the web server logs say about the transactions? Saying simply "No errors" isn't very descriptive. Are the requests reaching the server? Do those log entries appear any different from working requests? Can you ensure that your script is handling these requests as they are sent through (ie. are you logging)?

What web server are you running?

Right off the bat, please update things so that they use SSL. Asking a user for their personal information nowadays without at minimum SSL encryption is asinine. The "get it done at all costs" attitude before creating a proper backend is what the real problem is here.