Poor Service No Feedback

I have a good credit score, I have a private wealth credit card with FNB which is fully paid every month. I manage account payments, I meet the salary requirements, the reason I am applying for a diners club card is for the travel benefits. I am not asking for a huge credit limit, however diners club keep declining me with no reasons. SO why ? why cant you start me with a small limit in order to get the rewards and I can build a history with Diners?