Ariston Hotpoint Fridge Freezing Failure!

Ever since I got married in 2018, I've been really unhappy with the Ariston Hotpoint fridge I bought. I haven't thought about sharing my concerns until now, but I'm looking for a solution. The food I put in the fridge freezes when it touches the back. This happens in both the drawers and on the shelves. I don't get why it's happening, but I'm actively trying to find a solution. A lot of my groceries keep going bad over and over again. It doesn't matter if it's peppers, cheese, tomatoes, milk, olives, syrup, melons, watermelons, yogurt, or cream, some of them have already spoiled. Can you please help me figure this out?