Runny tummy the whole family from Freshline spar cake

I just bought a freshline cake for my daughter's birthday from nina park spar.The one with granadilla for R85.We ate it with my husband,3 year old (birthday girl) immediately when i got home around 5pm.My 5 year old ddnt want it coz she doesn't like sweet things.The cake was a bit dense and hard (not fresh) nut i just thought its the way they baked it. My problem is the 3 of us who ate it are having a non-stop running tummy.We are taking turns to use the bathroom even with the toddler