Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Ball Deflated After a Week

I love the exercise ball I have at home, I use it as a chair in my home office. I decided to buy one for my office at work and I bought this ball because it had the highest customer ratings. I used it for a week and then one day it deflated and couldn't be refilled with air. Luckily I didn't have a dramatic pop and get thrown to the floor.