What are your thoughts on this? What should we do?

Okay I just need to get this off my chest, and see if my husband and I are wrong in this situation. My husband graduated from high school in 2016 and his mother has his high school diploma and birth certificate. He’s trying to join the army and they need both! She won’t give it to him she stated “ I’ll give you a copy” mind you my husband is 21. She’s like what do you need it for? He doesn’t owe her an explanation on why he needs it. It’s his diploma and birth certificate!! What can she do with it? Nothing... then she called his step mom and dad saying he’s being disrespectful and if we come over she’s going up call the police on us. We’ve decided to take civil services with us to retrieve the items