Approved over the phone - branch says no - waste!

This is the third time I have app****. First I needed to correct something on my credit report, I did and that is now fine, then I go to the branch reapply and declined again agent advises me to wait another few months I do. then I do an online application it says approved go to your nearest branch and again declined this time because I look like I cant afford it because they calculated my salary as commission only i had to then wait another month before we could try again. I then said I will rather give up, so I did and on Monday African Bank calls me and I said okay lets give it a shot we did the online application and again approved and the call centre agent said I must just go to nearest branch to finalise application and give in my original documents. I did that this morning I get there the agent completes an application and AGAIN no offers available WHY am I approved then declined? there is nothing on my credit report to decline me? PLEASE explain!