Student Help! Keeping Nearly 2k Eur Deposit For Floor Stain?

Hi! My friend and I live in Paris for one semester for a homestay program. We had a host who gave us one room with no access to the rest of the house except the kitchen (with very limited usage) and a key to the back door (only one key, so my friend and I can’t leave or enter without each other).

Our deposit was 900 eur each, so 1800 eur. Halfway through the semester, our host came into our room without permission and yelled at us for the floor. We were confused but apparently the wood floor had small stains which has lightened a bit because water drops fell on them. We did not know the floor did this because of water, and our bathroom is attached to the room, so sometimes when leaving, small drops spill. The point was that we were initially never made aware until half way in the semester.

We were afraid she would do something to the deposit so we offered to help fix it if possible. She told us that the floor had to be sanded down and waxed, so we said okay and she bought the wax and sandpaper and we paid her. She showed us how to do it and we did a portion of it and she said okay. She asked us to do the rest of the floor but the sandpaper wasn’t enough and she kept delaying buying it (I have proof of this through texts) and bought it a few days before we moved out. We sanded the floor and she said she would wax it herself later. We unfortunately don’t have proof of this but she won’t lie about it because we kept documenting this in the emails to the homestay agency before we moved out.

Now we get an email from the agency saying that she said the floor was ruined and needed professional help and our deposit was on hold till then. But the photos she submitted was the sanded floor, not waxed yet. Before waxing the floor does look bad, but the wax completely fixes it, but it’s not been done? Is this a cash grab?

I want to ask if there’s a legal issue we can raise here because this is just false. And can we show up to her house to talk to her about this (we are back in paris for a short time) ? We said to the agency that we would bring a lawyer in and they actually started listening to us after that. Please give some advice ????