No valid reason for declining home loan

I am a customer with fnb for over 20 years, my salary gets paid into my FNB account. I have app**** for a second home loan with fnb and it's been a nightmare, from them not processing the application, to them lying and passing the buck, they don't call you with feedback and are totally stuck in ' the computer says ' mentality. They declined my loan based on affordability. They only take 50% of my rental income into account but what makes no sense is that they refuse to take my travel allowance into account because it varies every month. I supp**** them with 6 months payslips so that they can use an average which equates to about R 7000 PM and is clearly shown on the payslip but they still refuse. They however are quick to take into account my fuel usage as an expense. I am totally appalled by the way fnb is Hell bent on turning business away. I will be engaging other banks and will be definitely be breaking all ties with fnb.