I have been a diner's club customer for over 10 years and have paid on time all but two times. I was two days late with my last bill and was charged $100 for those days. I called to ask it be removed and was lectured by the manager, Lorna (code NCS0257) repeatedly and spoken to in a very rude manner.
I am redeeming all of my points and closing my account. Diners' club is a waste of time, get Amex. I have always recieved excellent customer service from them and their rewards are better.