Checkers Sixty60 - I am very dissappointed

I have been ordering from Checkers Sixty60 from the beginning. I usually order 3 to 4 times per week. Usually, I am very happy with my deliveries, until this week. Three days ago, the order that had to be delivered to me, was not delivered at all. On my Sixty60 App it shows that the delivery has been delivered 50 minutes early, but definitely not to me. So, I phoned them to complain, placed a complaint on the website and sent an e-mail to customer care. Out of three, not even one response. How can they not investigate and come back to me? I have paid +- R1000 for my groceries and received nothing at all.