Staff help themselves to what consumers pay for !!!!! And no response from Pick n pay

On Monday the 2 July 2018 , I bought drinks from the PNP Greenstone Mall Liquor store. Upon getting home my husband alerted me that one of the cans was actually empty without us even opening the 6 pack. you could actually see through the packaging that the can was opened and contents had been emptied and indeed put back. so I paid for a whole 6 pack , whilst some employee somewhere is helping them-self for free drinking what I paid for. What QC controls are in place? clearly none , I am not impressed with this service , it is unhygienic , unprofessional , I have pictures and if nothing is done about this I will take it higher. Nothing has been done about this and I will make sure to reach the top management of Pick n pay somehow. I received a measly response on hellopeter that this is taken seriously and nothing further. Does PNP actually have preventative action and internal quality audits done because it do-sent seem so to me. this was on the 2 July already.