Mamas I need major advice.

My sons dad and I are currently fighting for our sons custody & we're waiting for mediation that's on July. We both already have joint custody but he has been and still is trying to make it seem like he's the only one who has access to our sons decisions. Just yesterday he texted me saying he was taking our son to the dentist and I asked when was the appointment made and he called me saying that it was made last minute & were it was going to be but not provided me the address and he said he was going to send me the info once he got a chance but didn't. Then now today on drop off he tells me he's recording the conversation & tells me what they did on our son and ect but I reminded him that he didnt provide me no info & he gives me an excuse that his phone had died & since I didnt call him it seemed like I had no interest on our sons decisions but I'm fed up that he thinks he cant include me & now I'm asking what can I do in my case and say to him? Any advice, experience, stories will help.