Q: If my landlord states, “even if there is no animal urine,” but continues to charge me. Can I fight them and win?

A: I am not clear as to your current status - are you still in possession and an active tenant or have you restored possession to the landlord, moved out, and now are dealing with the landlord's accounting and attempt to charge you? One bleach stain sounds to be chargeable to you and they should be checking the carpet with a black light to show any organic residue rather than just subjectively relying on their sense of smell. It's unclear what the details are re late fees but you are, of course, entitled to an explanation/accounting for any/all fees charged. Ultimately, if it comes to it, you simply do not pay, essentially telling the landlord to put up or shut up. The landlord can then drop the matter; refer you collections (who in turn can only drop the matter or file suit in addition to just hassling you and harming your credit record.) or file suit against you himself. If he files suit, then it either will be to recover amounts he swears you owe or, if you still have possession, perhaps he would file to evict you. Either way, that would be your chance to defend yourself in court and get his case tossed out, likely owing you your court costs and attorney's fees. IF this is after you restored possession to the landlord and moved out, the landlord has up to 31 days after you restore possession to either refund you your security deposit and/or prepaid rent in full or provide a written accounting (note email or text does NOT constitute "written" notice) of how much they are keeping and why. IF you disagree with the explanation, you are free to file suit in court against the landlord. IF you win, you likely are entitled to twice the amount wrongfully withheld from your refund. You should always pay your rent in such a manner as you can later prove how much you paid and when you paid it. With that proof, it should be pretty easy to establish whether a late fee was justified or not.