Worst customer service ever

I just came back from Checkers Queenswood in Whittle Lane and Stead Avenue, I bought Similac TC no.2, cerelec and two purity juice for my 8 month old baby. Everything is packed except the milk and my child doesn't have milk for the night. The minute I realised he milk wasn't in the plastic bag, I called the number on the slip, the lady that answered told me they are closed, I should come tomorrow, I pleaded with her that my baby doesn't have milk she said I will tell my manager that you will come tomorrow at 8am. As I'm writing this email my son only has water to drink, what kind of a mother will I be to allow my 8month old to drink water when I paid R220 for milk I was supposed to feed my son. I have to now drive to Grasfontein to the 24hour chemist and spend R300 for the same milk I should've had in my plastic. You see the problem is when cashier, packer and another colleague have a conversation when they were supposed to focus on the customer that's when I have a huge problem. Checkers Queenswood has the WORST customer service on earth.