Have Apple or an Apple Authorized Service Provider examine the laptop. You may be surprised to find out you may qualify for a secret free battery repair program for swollen batteries if the laptop is less than three years old. We had several of our organization's swollen batteries replaced for free.
Edit: Some service techs forget about some of the secret free repair programs since Apple so many programs and has the details separated from the main public repair programs so you should ask them to check for a "Service Program" for "Enclosure separation" (assuming the laptop qualifies and the shop isn't cheating you - one of the dangers of secret programs).