Bad service and refused to refund

We ordered chicken livers at Garlitos Madiba Park (Polokwane) on Saturday and they came after 45 minutes and when they came they were cold. We were served by a security guard whom had a very bad attitude and was chewing bubblegum in a very irritable loud way when he was speaking to us. We then reported him to *****gwa Mawete as they said the manager was not on duty and we also asked for a refund as the chicken livers were dry, cold and not nice. She said she will not refund us and when we told her that we will report her she gave us very bad attitude and even told us to report her at the head office as she knows that nothing will be done to her. We were disgusted by the service we got from her and the fact that they made a security guard serve us while they know very well that he is not trained to work at a restaurant..when we asked why they chicken livers came after so long *****gwa said they were still preparing them but what I fail to understand is why did they come very cols as if they were prepared long time ago. When we asked her that question she just gave us bad attitude and refused to refund us.