We had confirmed that we do not manage the property, but we still tried to help and had conversation with the landlord and yourself as your relationship had become difficult.
I believe the landlord had provided you with an update GSI and his builder had attended but due to the way you spoke to the builder, he was not willing come back and the landlord had to assign other contractors.
We spend a lot of our personal time to try help both parties, when we bridged a common ground, the landlord was upset as you spoke to him in very rude manner after this. We did explain that this was not helping.
I feel your frustration lead to having communications break up between the two parties and I am also disappointed after the involvement we had even though we do not manage the property to have had such a harsh comment.
The landlord had confirmed due to the condition he received the flat back the deposit was returned once he knew of the deductions he wanted to make.
We always try to help but can only get involved depending on the service the landlord has paid us for, we went over our normal responsibility to help in this instance.