Bad service!!!

On the 02/12/2018 I went into Pick n Pay Liquor at the Galleria mall with my sisters to make a purchase. We then got to the till, however we were paying separately for the stuff we had purchased. The rude young lady at the till by the name of Mekayla (excuse the spelling, she had her tag hidden) allowed my sisters to pay then skipped me and started attending to another customer while I waited even though I was there before them. I then asked her Why she served people that were behind me first then she responded because we were paying separately. I then said but it doesn't matter because I was there first and with so much attitude she said well it does. I then went report this to the supervisor that was available at that time (Joey) He was busy on his cellphone, then I spoke to a lady by the name of Felicia. I am extremely frustrated because I am a paying customer, and everyone needs to be treated fairly. I hope she is reprimanded because her behavior was appalling.