HOMELOAN APPROVED THEN DECLINED WITHIN 2 WEEKS

HOW IS IT POSSIBLE TO BE APPROVED FOR A HOMELOAN THEN 2 WEEKS LATER BE DECLINED ..I don't know if these guys (call/assessor)are protecting each other ..because when I was declined my hubby went to the bank & a banker showed him the screen &he(my hubby)picked up on the fact that the assessor had duplicated my laon amount therefore I was declined for affordability...when I pointed this out to Nana the lady at homelaons call centre ..she sent me an email stating that I was declined due to Debt service Ratio I still cannot accept this & that there can be no consistency @ Nedbank.I need an independent person to look into this as Nobody has addressed, acknowledged or responded to the fact that there was an error in the assessment which I AS THE CLIENT had picked up & the bond which was approved recently never mentioned the Debt service Ratio.Nedbank had all the facts WHEN THEY APPROVED MY FIRST APPLICATION, Nana requested that I submit the new OTP to them and decline me for reasons which if reason enough should have been identified on the first approved application.I cannot approach other banks for time constraints and need an urgent investigation into this case.