Denied service by a Pick n pay (Osizweni) cashier

I went to a pick n pay(Osizweni) franchise liquor near my place in Mamelodi Pretoria to buy a bus ticket to vanrhynsdorp. When I got in the shop I guy got in to buy beer, I let the guy to pay first because I knew the bus ticket it's a process buying it., the guy paid and when I wanted to buy the ticket the cashier simply said she can't sell me the ticket what if a customer walks in to buy beer and I asked her does it mean that they are not selling tickets on weekends, she said yes and there was no manager to complain to and the cashier didn't have a name tag and she was so rude. I wonder why must they put plug cards of the service that are rendered but yet the services are not rendered on weekends. I avoided going to the shop because in the shop there was a que and I was going to hold the que and in the liquor store there was no que at all but I was denied to buy the bus ticket. Now I have to drive to get that ticket.