Poor service

I went to the east rand branch during their 3 year birthday celebration, as advertised if you buy a dozen doughnuts you receive a birthday doughnut for free. I asked the cashier and she told me she didn’t know what I was talking about, and when I addressed the issue with Krispy Kreme on Instagram I was told they would be in touch with me. It’s been a week and I’ve still heard nothing. No free doughnut as advertised and I received the wrong drink when I was there. Very poor service and customer care s****s.