Can you post a picture? If you are sure that it got swollen you definitely should not use it any longer. And if you have that battery for less than six months it is still under warranty.
If the battery swells from heating up I would not risk flying with it again, check the cells on the app and check if they okay or if it gives you an error.
Hi. Please send us a picture of your swollen battery so we can check. Just in case you were not able to use it, please contact the store wherein you purchase your drone or battery so they can replace if the battery is still under warranty. Thanks!