Opened yogurt tubs from Pick n Pay Northgate Mall

On Wednesday 12 August 2020 My husband and I bought 2 1KG yoghurt tubs at Pick n Pay in Northgate Mall as they were on special, today Friday 14th August 2020 in the morning as I was making breakfast I tried to open 1 only to find that the silver sealing paper was already open and the yoghurt was very watery, I checked the second one it was also open and yogurt in the same state, opened and very watery . I couldn't take it back because I had already thrown away the receipt and it would have been difficult to prove that I found them like that. Thought if the waste it would be to throw them away as I cannot take them back so I tried tasting one and tasted bad, not as well as it usually tastes as I had the flavour (which I got previously at spar) which had just finished before opening the Pick n Pay tube. 5 minutes later had too much gas bubbles in my tummy , I drank lots of water to try and wash it out. I am extremely disappointed as I had never experienced this at Pick n Pay Northgate before . I then threw them away