Rotten chicken ruthless & Degrading customer service in

Recently I bought 3 4kg bags of rainbow brand frozen chicken at ShopRite in vangate mall however I did not use my shoprite savings card hence I forgot it at home I dropped the chicken at my mom's as she has a feeding scheme the chicken was going to be used to make a pot of curry my mom immediately noticed after the chicken defrosted that it was brownish in colour some portions had greenish colour to it and it had an awful smell we then checked the expired date or manufacturing date all the bags had none I then immediately took the chicken back to the shop I spoke to a supervisor I explained I bought the chicken the day before around 6 I used another customers extra savings card the slip was still in the bag but got abit wet so it was a little faded but noticeable the supervisor refused to exchange or refund me the way she spoke to me was so degrading i was embarrassed she went on to telling me who says i really bought the chicken at the shop even showing her the receipt you could still see the branch time and date she then took the receipt and through it in the bin I then said I'm going to contact customer services she felt so entitled and laughed at me saying sge doesn't care , im a business owner iv never seen anyone handle any situation like this since then I have not shopped at ShopRite I don't think I ever would