Very bad service

I received very bad service at Mr price Alberton city from a cashier called Nhlanhla. My partner and I waited in a long queue for 30 minutes waiting to be served, just when we were number 2 in the queue a random guy decides to cut the in the queue, Nhlanhla called the next customer to be served this random guy rushes to her and we complained that she should not be serving this guy because he didn't join the queue instead of her sending the guy to join the queu like every other customer she just said to us she won't attend our query she's going on lunch and continued to serve this guy immediately after she logged off and left us standing there all the other cashiers said nothing and continued with what ever they were doing even her supervisor bear in mind no name tags were worn I had to ask her name from o e of the cashiers. The customer does not come first from that store they serve who ever they want.