Noncustodial Claiming on Taxes

So for the past 2 tax years my sons noncustodial father has claimed him without permission. Has anyone ran into this problem? He doesn't carry him on insurance, no support, nothing. Which is fine, but I talked to my lawyer about it and even tho taxes aren't addressed in my custody order he said that I'm entitled to it every single year since I have written primary custody.

I realize that since mine were electronically rejected that I'll have to mail mine in. I sent them the appropriate paperwork for the last tax year that this happened but no response from IRS. And he pulled the same stunt this tax year. My mom did inform me that once she had to mail her taxes in 10 separate times before as the IRS kept claiming they never received her paperwork. So it's very possible that I sent it in and it's just sitting in a mail room still unaddressed or got lost in transit I suppose.

But if any of you other ladies have had this happen, what was the most effective action you took in resolving this and preventing it from happening again in the future? I thought about trying to contact the IRS directly over the phone and just explain to them what is happening but wasn't sure if they'd even really care to help me. I don't care that he isn't paying support as I can support myself but this is just outrageous to me.

Hoping maybe we have some tax savvy ladies here! Thank you!