Not claiming responsibility

I am currently using my 2nd Samsung device and purchased the device last year. My battery has never had a lasting charge. The battery is swollen and i know that samsung reported faulty batteries in a few samsung devices and they replaced all those of which clients complained. I tried contacting their Nandi drive office *** 4 times with no answer and their gateway samsung store *** and after numerous calls they answered and told me i must pay R499 for the battery. I then started a live chat with Frances on the samsung website and i was advised again i must pay for this because the battery has a 12month warranty. They know their batteries were faulty why should i know fork out R499 for a new one. If they cant accept responsibility i will have to move onto Iphone like everyone else. I am so disappointed in the service.