Spoilt cheese

I purchased a block of cheese on saturday from spar in chatsworth yesterday morning my sister opened it to make biscuits for my mother not realising the cheese was green all over and she is small so she didnt know my mum came and said it wasnt tasting right so she couldnt finish it, after a while she felt sick and started throwing up and because she is a sickly person and has a heart condition her body is not used anything different she throws up at this point in time i was still not aware what had caused it when i went to use the cheese cause i was preparing something i then see its green all over i then took it back to spar to return it because i cant be paying R100 for cheese thats green all over and mouldy, however i had to take another cheese because i was preparing supper and i couldn't tell them much as its not there product, ever since my feels like sick to her stomach