Rotten Eggs - Clearly the sell by date is just for decoration!

A week or two or three ago, I bought a tray of Pick 'n Pay eggs. Well, at least half of the tray is off. I have ruined two cakes, and other items that required eggs, but the cherry on top of the so called cake was when I boiled eggs for breakfast and one rotten egg exploded. Oh my goodness - how revolting. Is there not quality control - there was no problem with the sell by date when I bought the tray! I find this quite off putting and disgusting. Clearly there is no recourse as I never kept the packaging nor my till slip. A warning to all out there - stay away from the eggs that are sold at Pick 'n Pay!