Ex took 400 from my bank account

Let’s just skip ahead to when he broke up with me a week ago for dming my guy best friend since freshman year, on Instagram. Many times has he broken up with me over the dumbest things, he wouldn’t forgive me for this. It’s unfair because I’ve always forgiven him for being abusive, controlling, and manipulating me. But that’s not the point. I’m just curious of why days after he breaks up with me, he chooses to take MONEY out of my savings and send it to himself, saying I owe him for the money he’s spent on me. That was like a week ago okay, so yesterday I asked him when he’s gonna give it back. He said he’ll pull the money out of his bank and leave it in my mailbox when he’s free, I said he should do it by next week. He said no and that I only wanna spend it. I’ve tried changing my password so many times, but he can still log into my banks app. I just don’t understand why he’s using this money thing as an excuse to talk to me. I needed someone to talk to about this, so sorry if this was too long ! It just upsets me !! I need him to give me my money back so I can go to the bank and take him off completely ! It pisses me off that I loved a guy who’s put me through so much shit and finds small faults to accuse me of ruining our relationship. I’m sick and tired of it ! I wanted this guy in my future, but I’m slowly becoming disgusted with the way he thinks. I’m truly disgusted with him in everything he is.