Hi there – we too have had a huge £13k bill from them for work on our block on Highgate Road. I’ve already written and complained but been rebuffed by the inept staff at the council. I asked about the extremely high fees, especially the overheads and Indirect costs.
I’ve also written to our local MP Kier Stramer and he’s been receptive to our case before. I suggest you do the same so he knows it’s a major issue for some of his constituents.
Let me know how you get on.