My son signed a contract to use a trainer

I established a gym membership for myself and children to use together in order to stay fit.  My two sons went to the gym together and had an assesment done my one of the trainers who then talked one into signing a contract to be trained which is 150.00 a month.  He thought it was 47.00 a month which was not fully explained to him in terms he would understand.  When I found out I contected the gym and asked them to cancel the his training.  They printed me out a paper for cancelation and told me to send it to their corporate office which resulted in their office sending a email stating that they would cance after my son paid another 150.00 for the service which he never used.  resulting in 300.00.  This is definately a scam by making people pay two or more months for a service.  LA fitness should be ashamed that they coax people and minors into training that is real expensive and mislead their information by making it sound less than it is.  I will be cancelling my whole membership and go to planet fitness which is cheaper and they do not push there training and not to mention you can get a membership for less than 20.00 a month.