Inconsistent and incorrect lending eligibility and poor ability to explain why

I used my online banking app to see what I would qualify for in terms of a revolving credit or fixed term load. I was eligible and could see what I was in for. I was still in two minds so did not take up the load. I was also contacted by a banker to see if I need assistance in taking up the loan. I have more than enough funds, I save with standard bank and have a home load. I tried to apply today via the same channel - and the app says I no longer qualify? How ridiculous. I phoned a prestige banker who told me they cannot tell me why I am no longer eligible and that I had to phone the bank during work hours and apply for a loan. This is such bad service and an inconvenience since my credit history is was in the green with standard bank. Shocking service,. Not happy.