Rude till packer

Good evening. So I went to buy nappies for my son and as I was about to pay my checkers specials card was rejected. As the till lady was helping me with a new card the line behind me was getting longer. The lady next to her offered to go open another till to open the customers being me, the till packed in the next till shouted at her to leave those people they will wait I went on to ask her if customers should wait while they can get help and she told me that's what they are used to doing..... I mean she has no shame to say that while customers are waiting in line. Wow.