Forfeited deposit and extra charges

I was a resident at City Propert flats,Station Place for a period 2020 January 10 - 2021/ 2021 January 05. When I moved out, I forfeited my deposit because I moved out before the 31st of January 2021. I notified the office that I am moving out on the 5th of December 2020 and I never a letter stipulating what should be done when I move out. When I moved, I cleaned everywhere in my unit but did not collect the ******* and put in the bin and I did not leave behind the key. Now they are charging me R600.00 for throwing the ******* in the bin and R300.00 for the key.