Refurb Galaxy S5 as Insurance Replacement

In May 28 I bought an Galaxy S5, Since the beginning the phone got hot, than the battery would not last long, than the phone gave the message was too hot, the camera would freeze, the flash light would turn on by itself. On June 27, I called customer service; they told me I could go to the ATT store where I bought it. When there the manager told me I have to go to the customer service center in Guaynabo. When there, they told me that they did not have the phone, fill out the paper work and told me they would be sending me a new phone. We waited for it, received it today, gat a rebuilt. When I call the song change, they could not send me a new phone. Could you believe they want me to pay $650 for a rebuilt phone? The phone have not been drop or damage in any, it must be a factory defect.