Selling expired baby formula

I have complained on numerous occasions about the bad service and *********** staff at Clicks Broadacres, 2 weeks ago I bought s26 baby formula from Clicks Broadacres ( spar had no stock ) for my baby who was 6 weeks at the time, for 2 weeks I've been sitting with a baby that's suffering from bad cramps only to find that the formula expired in 14-05-2017