FNB letting down their customers... I feel like I should change banks

Good Day I would like to lay a complaint against FNB credit card division. I had app**** for a credit card last year Dec. They declined me advising that there were accounts on my credit report which were in arrears. I advised them that those accounts had been settled early last year and that I had the paid up letters, I was then asked to forward those letters back to them to assess and rescore my application. I never heard anything back since December 2018 so today I call them to follow up apparently my application was work on on the 4th Jan and declined again and no one had the decency to call me to inform me of this. The reason for decline, is once again those same account which I provided paid up letters for as well as the face that my exposure on the bureau exceeds my monthly income. Now I have explained to them that I receive rental income for my bond which is paid directly into my bond account monthly along with the lease agreement to confirm this. I also have an agreement in place for one of the vehicles on my name which I don't pay for the debit order runs directly off my dad's account and we have a witted agreement in place confirming that he will pay for the car and has been doing so for 3 years. Now I need my bank FNB to consider all these things when resubmitting my application or else I will report this straight to the CEO and move all my accounts. I started banking with FNB as I thought they were one of the better banks but they keep proving me wrong and I will take this as high up as I can to get the customer service and satisfaction that I require!!!