Disgusting client care product related

I bought milk in end November as I do on a usual basis ad to my surprise after opening it it was sour. I've email there customers care showed pictures clearly showing it was the pnp brand of milk. And all because I have no slip or did not probably swipe my smarts hopper they could not attend to my request. Disappointed and disgusted. I will return as a customer once they show some decency when these things happen as if I keep slips for damn milk for a retail store I TRUST. Until this is resolved I will do my kids shopping at a different retailer but clearly you guys don't care.