Poor service

I have app**** for Building loan with the bank, the application was approved on principle pending the evaluation, the evaluation department decline my application without providing reason. the other bank ABSA has approved the same application. I have been banking with nedbak for more than 15 years and felt the bank should advise me with the way forward as I have already bought the vacant land I have then lodged a complaint with the complain department reference number ***, and the Jason Jordaan came back to me that the application is declined because of affordability, I have pleaded with him that I will pay the shortfall, he however said I must take the matter to banking Ombudsman. how can the bank that I have been banking with for so many years fail to provide to me what other are prepared to take risk on?