Refusing to be assist customer

We went to the post office to purchase an envelope, when we entered there was one lady at the que, we stood behind her, she then went to the teller to be assisted and when she was done when it was our turn to go to the teller to be assisted, Nomakhosazana Sello the teller, did not want to assist us and called someone that had just entered the post office to assist him first, and we left the post office without being assisted. And the manager saw everything that was happening and all he did was giggle.