bad service at shell garage

I have never been so I'll treated on Sunday 25 February 2018 at 8:00pm went to my local shell garage on the Springs road waited for half an hour for petrol just when it was my turn a lady from nowhere decides she's not going to wait and goes at the back of the pump and gets service'd, when I try to explain to the petrol attended that I was first he didn't bother and continued to assist this person who came after me. I then left and never came back, I'm so ****ed at the unprofessional behaviour of the petrol attended and the value of the garage!!!!!