Hisense Infinity Pure 1 faulty battery

I bought my hisense phone in February this year. 8 months down the line I woke up one day and tried making a call but my phone just went off at 89% of battery life. I opened the cover and my battery just swelled and since then I can't close the cover with the battery in properly, and my phone always has to be on the charger in order for me to use it. At one stage it will say 100% full but when I pull the charger out it just goes dead. Finding a battery is very hard especially for your hisense phones. The phone and it's features when it was being advised promised a long battery life but I am very disappointed especially because I had to travel all the way to Rooihuiskraal just to buy this phone because of the way it was marketed and being compared to the iPhone 6. Please advise where in Johannesburg it is that I can purchase a new battery. And since the phone is less than a year and the fault seems to be from your side shouldn't't it still be under guarantee for faults like this??? Please revert to me the soonest. When one of your products proves to be faulty then I will fear purchasing any of your appliances fearing that maybe they might also become faulty or explode!