Hopcoms — Arrogant behaviour

I had sent my niece to get banana, the banana she bought was completely riped, as it was already night, I decided to go and return it on the morning. When I went in the morning to return it, the person was too arrogant and told me that he won't take it back, when I told him that I'll complaint against him, he was least bothered, he told me I can go and complaint wherever I want. And this is not the first time he is doing this.