Faulty products

I went into your store in centurion jean ave to return a hair straightener that is faulty, first all the manager has no respect to the customer, I can understand you speaking to your staff but when a customer is in front you, you address the client, you don't give the buck to your staff member to say. Second of all you tell you to exchange the product, but you don't have stock of the item I want and then you become defensive with me!! I'm sitting with a straightener that works when it feels like and I must just be okay with it??