Not adhering to returns policy

I wanted to return a sweet melon that i purchased for R30. Upon arriving home i attempted to slice the melon. It was completely rotten on the inside. I went back to the store almost immediately to return it. <br> <br> The manager was no where to be seen. The lady at the till refused to take it back as it was already cut open and i had no slip. <br> <br> I think this is unnacceptable, i do not think a lot of people will keep a slip where you only bought bread and a sweet melon. I am dissapointed in the attitude of the lady at the till and that there was no manager on the floor.