Sadly she does have a deposit of £2500 and we've had no sign of any of it yet. Any advice on what we do next?

Hello, We've just had a nightmare year of renting. in a reasonably expensive flat we've experienced periods without heating, periods without hot water, periods without any water and a major flood mostly due to an old and ill maintained boiler. We've had requests for things to be repaired ignored and despite having paid a cleaner to come for 3 hours a week every week have been accused of keeping the flat on a "filthly" condition (we are 3 pretty tidy girls). As we approached moving out - mostly to get away from this landlord we anticipated problems so offered to have the place professionally cleaned (it wasn't when we moved in but we figured this good will gesture might avoid further problems). We agreed with our landlady that since she hadn't relet the property the cleaning team would come in a couple of days after we left so they could do the most thorough job with our stuff out of the way. She was thrilled at this idea. The cleaning team missed the first appointment to do the house as they had a car crash on the way there. The agency organised a replacement team for the next day but the landlady is now demanding rent for the half week between us leaving and the cleaning being done as the property was in an "unrentable condition". She agreed to this and made no noises about extra rent - otherwise we obviously would have had it done before we left. Can she do this? Also, she is claiming lots on the damage front. There is a small mark on the wooden floor from a high heel (we which concede was probably us) but she wants to sand down and revarnish the whole floor! Finally the large sash window in my room was broken when we moved in, i told her about this last november and she said she's fix it (it was broken such that when you released the catch to open the window the top pane of the sash window crashed down to the window sill as the catch was the only thing holding it up). She hasn't had it fixed, despite us having a massive heatwave and me repeatedly saying the problem was the hot weather. On the day we were moving out someone helping us move opened the window to air the room and the pane of glass broke. She wants us to pay for the repairs. Our friend couldn't have known the window was broken by looking at it but she is saying it was carelessness. This seems unreasonable to us - what can we do? Is there anything we can do? All advice appreciated.