Rental deposit - unusual situation

I am having problems recovering my rental deposit and my situation is quite unusual, so I would appreciate any help or advice.
I lived in the apartment for 5 years and moved out at the end of March (I no longer live in Belgium). I rented the apartment from Landlady A, who sold it to Landlady B a couple of years ago and never had any problems with either of them.
There was no official inspection when I moved in. I had composed a document with some photos and a list of the main damages (many of which I repaired with my own expenses), as there was an understanding with Landlady A that this was an unrenovated 1960s apartment and had its problems because of its age. Landlady B was also aware of this fact.
Sadly, Landlady B died shortly before I moved out, and the apartment now belongs to her daughter, Landlady C, who had never seen the apartment before my moving-out (unofficial) inspection. Although I showed her that I was leaving the apartment in a good condition (actually, in a better condition than the one I received it in), she now wants to charge me for pre-existing problems, for normal “wear and tear” and even for damages that the next tenant caused (claiming that I was responsible for creating a problem with the infrastructure, which is absolutely not the case).
Of course I explained everything in detail and refused to sign anything, I offered to contact Landlady A to verify the pre-existing problems and even offered to pay for half of the “wear and tear” expenses, but I am not sure how to proceed.
I read many of the previous posts and I understand that Belgian laws generally favour landlords, so I would appreciate any ideas or advice on what to do next to get my deposit back.
Many thanks in advance for any replies.