The owner may take certain costs out of your deposit, and what they can and can't bill you for depends on the jurisdiction, but it is certainly illegal to keep

The owner may take certain costs out of your deposit, and what they can and can't bill you for depends on the jurisdiction, but it is certainly illegal to keep your deposit without giving you an invoice for the costs. If this is what happened in your case, you could take your landlord to small-claims court to get it back. As general advice, anyone who is leaving a rental property would be well advised to take pictures of the whole place on the day they vacate, in case they have to debunk damage claims by the landlord.