Low Fat Red Milk Cartons at Pick n Pay, dysfunctional caps

Pick n Pay Wellington - I bought a carton of 6 Livewell Low Fat Milk in July 2024. On using the first one, the whole "tamper proof cap" came totally loose off the top of the box. So I thought ok its one box in a lifetime, no problem. I then opened the second box and milk was oozing out of the side of the cap, the seals were not working. On the third box, as I open the cap, the whole plastic thing spins around ... does not stay glued to be able to use the cap effectively. When I went to Pick n Pay to tell them, they said they could only give me other boxes of the ones I have not used, but I must return them first. LOL - so what happens to the ones that were broken? Ill have to buy another brand in the future - because these dysfunctional caps cause the milk to go sour.