Bad customer service

I'm not happy with the service that I always get when I visit BP garage to pour petrol,every time when Gladys assist me she treats me like a ***** because everytime when I'm there she insists on swiping my card first before she can pour petrol,when I ask her why she is doing that she says that is the procedure and she is following,sometimes she will say the machine will go offline hence she is swiping the card first or what if something happens and who will be responsible for the payment,her colleagues(Mbali the Manager) don't do that to customers but when I ask them why is Gladys always doing that to me they say it is the procedure.I always feel humiliated by Gladys and her service.