My Pink Leopard Ultra Battery Case

How do I get my Pink Leopard Ultra Battery Case to work. The battery Case won’t charge. It also won’t charge my iPhone 8 Plus. It won’t turn on I don’t know if it’s dead and that’s why the case won’t turn on. I read on the internet the case will show a light when it’s charging but it don’t show anything. I also read the case will turn green when it’s fully charged I don’t know how to work them I just got mine tonight but I bought it from someone. So please someone help me. Before I bought the battery Case she told me everything worked so I’m hoping that I didn’t get ****** over because if I did I’m going to be so mad. I paid 100.00 For this battery case.