I am sorry that this happened to you. Without knowing more of the specific details it is likely one of two possible things, either the mortgage professional did not properly qualify you for your pre-approval (by checking your last 2 tax returns, etc.) or the home did not appraise. It is very hard to answer this without knowing specifically where you were in the process. I would recommend that you discuss this with your mortgage person first, and would consider switching to someone that your REALTOR recommends. Best of luck to you.