Not sure how to handle this deposit situation. Seeking advice

[Quandra Adams]

My tenants moved out on August 25th. No notice was given. I happened to see the U-haul in the yard and went outside to speak with him. That's when I found out they were leaving. They paid for 3 months up front which was supposed to be through the end of Sept. They left behind furniture, tables, electronics and a few more things which I and my boyfriend had to remove. He keeps asking for his deposit and is either trying not to understand why he shouldn't get it back or does not want to understand. I'm in NC and this is my first rental and my first situation like this but I am not sure how to proceed. 

Looking forward to your responses.