Very poor customer service

Poor poor service from the staff at BP express Glynnwood in Benoni, they didn't take out the promo stickers for the monster promo that was running dor the previous weeks, when i got to the till point the cashier by the name of mbali told me the primo is finished i told her its still advertised that the promo is still running, she then called the guy who was in the next till who had no manners, very poor customer service who was trying to explain to me that they didn't do their job properly. They were both screaming at me in front of other customers.