Feedback/Response, Pre-approval for what?

I went to Betterbond with confidence and hope that they would assist me in getting a bond. I first app**** for pre-approval and was assisted by Karaden, sent all the necessary documents, and 1 or 2 days later I received a pre-approval certificate which gives me the go ahead to continue with my search for the house. Charmaine Crawford then took over from Karaden as she is the one who will send my application to the banks. She requested additional documents and I sent them immediately, she then went ahead with the application. It was thursday when she took over from Karaden, Tuesday the following week she sent me an email saying I got this offer from one of the banks and asked if I have an additional shortfall, that is if want to continue with that bank. I rep**** immediately to her email, she never came back to me. I wanted to know if she had app**** to other banks and so forth. I then decided to call her, that's when she told me I did not qualify at other banks. She didn't send me anything in writing, the last time she sent me an email was when she sent the offer from the bank. Right now I am lost and confused because of the manner in which she handles my case, because all along we were communicating via email, suddenly she kept quiet and does not respond to my emails. I thought better bond was there to assist you all the way, to advise and ensure that one does in fact get the bond otherwise I would've app**** myself.......I really am disappointed and am not satisfied with the feedback I got from her....Otherwise why do a pre-approval certificate if the application is gonna be rejected?????