Ex Baby Daddy Is Taking Child Out Of Daycare On My Day

i recently found out (on accident) that my ex has been taking our kiddo out of daycare on my days for random reasons & bringing him back before i pick him up at the end of the day. i just got a call from a therapist confirming my appointment time (with my child that i didn’t make or even know about) that he had scheduled. the insurance is under my name for my son & his dad is taking him out of daycare on my days without my knowledge. is this or can it be considered kidnapping/fraud/violation of our custody agreement? my ex does not communicate at all with me & when he does he’s verbally abusive. we also have 50/50 custody with no child support. tia