Bad service

Tuesday 6th February I purchased a rotisserie chicken and wanted to use my discount reward voucher. The cashier could not complete the sale as the voucher number came up as invalid. She called her supervisor and after a few attempts she referred me to another cashier with no success. The supervisor then proceeded to a workstation to investigate. While she was busy, she chatted in her own language to four other cashiers in close proximity and this resulted in all these cashiers turning around and staring at us. 15 minutes later, we decided to pay without the rewards discount and left with our luke warm chicken. At no stage was any apology offered. And up until today no contact from Woolworths regarding my email. Disgusting service.