If I understand you correctly, your ex-spouse or partner has violated a court order about once a month for the past year--no Judge likes his or her Order to be disregarded. If you already have an attorney who has initiated a contempt action, great, and if not, I strongly recommend hiring one. A local attorney will not only be able to give you a better idea of how a judge might rule on your contempt action (given the specific facts of your case), but the attorney may be able to tell you whether a modification of custody is appropriate. If your ex's actions are negatively affecting your child's ability to participate in school or school-related activities, modifying your current custody arrangement may prevent similar difficulties between you and your Ex from arising in the future.
You need to contact an attorney and have all the facts evaluated. A contempt action including a change in the visitation orders or a petition to modify custody might be in order. Judges do not like having their orders ignored nor do they like having children used as weapons in some petty vindictive actions.