You could email back the pres with what the issues are, but he might just email back and say that you and the other parent are the only ones with the problem and that it wouldn't make sense to have a meeting for 2 parents if he is already so defensive and unwilling to talk of the issues...so maybe you and the other parent could ask around the other team parents what they think, if they have issue with it, and then go to the president, the coach, and the gym owners as a group.
Also, mention that the less number of gymnasts that compete the less number of people the coaches' costs and other related fees that are divivded among the team gets divided into, so then other parents have to pay more. Why can't extensions be given? The team classes most likely have the lowest cost per hour of instruction compared to the rec classes, so it would be in the interest of the gym not to lose team members, and also not to restrict them from competing because of them needing a payment schedule - how can they attract new members to their team program if they don't have a competing team.