SAB product incomplete

On Saturday 2017/08/19 I bought a 6 pack of Castle NRBs at PnP liquor Willowbridge. When we got home I opened it and to my disgust one of the bottles had been opened and the beer consumed. I called the store and spoke with the manager Damien Baartman. He first spoke with my fiancee and had absolutely no empathy or showed no show of good faith and said it was the SAB staff on the truck or in factory who probably drank it. So how will SAB or PnP treat it's loyal customers and what do I do in this case?