THE FIX REFUSED TO GIVE ME A REFUND

I bought an item at The FIX Soshanguve Crossing Mall in December 2024 and the item is not fitting and needs to be altered if I was to keep it and today I went for a refund and i was told that they cannot give me a refund as I lost my receipt and I told them that they can check my TfG transactions as I used it when i bought the item and they said thats for points not to trace transactions and when I suggested that they check their copies they said the cant use their own copies to refund me. I was assisted by ladies who did not have name tags on. What does one do in this regard?