PROMISED BUT NOT DELIVERED

Please advise how I can go about cancelling my contract with Zone Fitness, without being held responsible for the remainder of my contract. I signed a contract without viewing the gym as it was still under construction. I was promised that the gym will have a kiddies section. To my surprise when the gym opened there is no kiddies area. After numerous emails I still do not have satisfactory answer. This was my entire reason for joining the gym. Also I was there once and the gym is so busy that you cannot gym properly. I have the thread of emails if your require this.