Hi, I would like to lay a complaint against Debonairs Tshwane Mall

Hi, I would like to lay a complaint against Debonairs Tshwane Mall. I order on Sunday 3 pizzas on the one I found big pieces of raw onions on it. I informed them about the incident and they said that they will get back to me. That was on Sunday. I'm still waiting for a response. I'm about to delete there app and never purchase anything from them anymore.