Homes for Haringey annual service charge increase of over 700% for communal TV aerial!

Hi all.

Just had my 2019/2020 service charge from HFH and I am amazed to see the annual service charge for our communal aerial has been raised from £13 to £106! How can this increase be justified, especially as no one ever comes to maintain/service it as it has loose cables hanging down from it & no trunking etc. I live in a small block of 9 flats and what I pay is 8.33% of the total for our block, making the actual charge including the rest of the flats a whopping £1272.29.

How can HFH justify this costing for a over ten year old aerial setup that hasn't been serviced for years? 

See attached photos.

I'm all ears if anyone can reasonably account for this increase.

Thanks.