Rude telephonical customer service

An African guy whose name I do not even know from Mynt Cafe in Camps Bay ruined my day. So I am calling this guy regarding my wikideal voucher because I have abou 3 at home so I wanted him to check which one is valid for me . The guy answered" I'm too busy now for that" In my life I have never received such a ridiculous customer service. @Mynt Cafe , kindly train your stuff on business etiquette,that was the most ridiculous answer i have ever received in my life