FNB’s failing loan facility

So i have been banking with FNB for About 2years now, i Have never had a return debit order in over a year, my salary has more than doubled while with fnb my credit score is above 585, FNB has been offering me Temp loans almost every month the amounts vary from R3500 to R9000, i have been taking these loans and paying them back at a go.

My problem is, FNB seems to be refusing to leaned me a significant amount of money, if i am able to pay back a R5000 temp loan I should be able to pay back a R100000 loan with in 48months. If this doesn’t change i will be switching banks and moving my salary somewhere else.

Someone kindly address this matter Asa