My Former Landlord charged me excessively

Location: California

I used to live in an apartment owned by a major company. My lease ended on July 19th, and I moved out on the 17th. I informed them of my move-out more than a month in advance, although my lease had something about a 60-day notice. More than 21 days after my move-out, I got a statement. Keep in mind that the only thing the move-out inspection noted was the touch-up paint in the living room. They charged me for the cleaning fees and the paint fees. They also charged me over $900 for “rent through lease’s end.” I asked them to send me the receipts for the final utility bills, as they were higher than any month we lived at the apartment, and to return my full deposit since they had passed the 21-day deadline and had forfeited the right to keep any of it.

However, after reading that, they sent me a new statement, charging me almost a month’s rent(which is more than $2600) for “rent to relet.” As far as I know, they can only do this if they incurred any meaningful loss. For only two days, this is unreasonable. I would like to know my legal standing on this and what I should do.