Worst service

Worst service ever at McDonald's lenasia rude staff at the restaurant I came in at 20:00 on the 12/09/2019 and the lady at the counter wasted time rude when I asked her why shes taking so long to redeem the voucher eventually the voucher expired and she just ignored me and called the next customer and when I asked why she did that and what's can she do to redeem it she just says nothing and and looks away really pathetic service