They take your money in the name of "admin process"

I gave notice that I would move out in May, on the 15th and was told that I still have to pay a full month's rent. I ended up emptying the locker on the 25th of April and now being harrased by them wanting more money from me, this is after they have already taken my entire deposit and debited my account, they want more money. Biggest mistake I made and reading other reviews, I'm happy I was able to get my possessions out otherwise they would've kept my things and locked it up.