Dishonoring Parental Agreement, Seeking Custody Change

[Grace]

Hello...and thanks for taking the time to read my post.
I have a Final Judgement which enforces a Parenting Plan. That Parenting Plan states that we, the parents, have equal time sharing and parental rights including: shared decision making in all major decisions concerning the children; and a detailed time sharing plan. The violation: our 14 year old was sent to another state and enrolled in boarding school: this interfers with my right as a parent, most importantly inteferrs with our visitation schedule.  Via numerous forms of communication I clearly stated I was not in agreement with my 14 year old leaving to another state to go to school; my rights and wishes were not honored. I have a hearing before a magistrate in a month. I have never been before a magistrate...any suggestions on how I should prepare to demonstrate "subtantial change in cirmumstance" to merrit a change in custody?
Also: my 14 year old was bribed into going to the school, among the many bribes, he was given access to a credit card acount; the school has been made aware that I am not in favor of my son attending the school; the school requested that I give consent to have my 14 year old work, I declined consent, but he has been employed anyway; my 14 year old's grades are not any better in the new school compared to the public school he was in prior to all this (all Cs and Ds).
This situation has caused a rift between my 14 year old and me: he won't call me, and hardly replies to my call or texts; when he does reply all that is said are cover-ups and lies.
Supposing the magistrate rules in my favor...will I be harming whatever relationship I may have with my son?

[MixedBag]

1.  What state and country are you in?

2.  What was the reason for the other parent to change schools to a boarding school?

3.  Are you being asked to pay any of the bills associated with the school?

4.  Are you JOINT on the credit card?

5.  Who claims the child on their taxes?  (due to employment)

6.  Is the school following child employment labor laws?

Are you endangering your relationship with the child?  At that age, since you say the child was "bribed" -- be careful how you tread and read Divorce Poison.

Maybe you should ask the court for a new parenting schedule -- let the child go to the school and in exchange to get back as close to 50/50 as possible, every day that the child is "off school" and at home or not at school should be spent under your roof.

[Grace]

Thanks for responding.
I live in Florida; the reason for changing schools "(our son) wants to have a closer relationship with God, and I am going to help him with that"; from the begining I made it known that I will not contribute to the school as I am not in favor; I am not joint on the credit card; the other parent claims the child on taxes; I don't know what the school is doing (they have not replied to my emails regarding the employment issue).
Thanks for the advice on the resource.
The other parent has already "rearranged" the schedule without regard to how this may affect me (my work schedule). For example, the child goes "on leave" in a couple of days and I have received an email from the other parent which details the hours that I will be "allowed" with my son.
In mediation the other parent slipped and stated, out loud, that the intent is to keep the children as far as possible from me; when confronted by the mediator "clarifications" were made on the statements voiced-the mediator didn't buy it though...but that does not help me. Since mediation is confidential, I have no way of proving the other parent's intentions. The other parent is just a very malicious person and has done so much to ruin my relationship with my children, and worse, the court system has empowered him by letting him get away with so much.