Bad costumer service

Today I went to pick n pay maponya just to get a few things as I was waiting to pay on the tellers the machine that calls on costumers to go to the next available teller was on but wasnt displaying the number of the till so as I was trying to figure out which cashier it is I asked this lady if she I come in, and with an attitude she tells me didnt it tell me which till i should be going on worse she is an older lady her name is Nokuthula Buthelezi till no.29 . I usually get good service didnt expect it especially from this store. I believe costumer service is stil required and respect.you will never know who you are serving.