Refund

I purchased a cellphone 3 months back last on the shelf but 3 months later the battery is has gotten fat and the phone switches off at 95%. For a product purchased R1100 i feel cheated as when i took it to the store they told me to hand it in for 2 months so it gets a new battery. Even the most chinese phone battery lasts a year before it starts giving you problems but this one lasted 3 months. I feel the battery that was given was either long instore or not original. Why sell it moreover take my money for a product that has guarantee but the when going to claim such errors im not assisted. This is worst customer service. And im dissatisfied with this product. I want my money back as this is unacceptable