Bad service

I bought a kitchen scale (Clicks brand) in Harrismith Free State, when I got home it worked well for the first 2/3 days after that it was not. I tried changing batteries but still nothing. I then went to Clicks in Qwaqwa to change it, and they asked for the receipt and I told them I threw it away. I was then told that, I couldn't change it because I don't have the slip, mind you it's a clicks brand where else would I have gotten it from. Now I am stuck with something that doesn't work, what crazy logic behind not wanting to change it for me.