The other thing is Jay, service charges are no levied arbitrarily- they are based on previous years actual costs, current years expected increase in costs (VAT, geneneral increases in costs of delivering services) as well as budgeted costs for work they know needs to be done (although some costs may be spead over a number of years)
As you know, the cost of everything has gone up a lot recently, and if there is maintainence work that is needed to be done on the properties, either because of wear and tear or because people are not looking after the property then this may be a factor. Have a look at the charge schedule and comare is to last years- you can then look into what has increased.
Often there are lots of little charges that add up to something big because of small repairs: broken glass in doors, lock changes, furniture left in the bin stores, graffiti (and so on). Often in blocks residents don't give much thought to how graffiti mysteriously gets cleaned up or that old sofa got removed, but in reality, ANY communal service, from the cutting of grass to the washing of windows, is paid for by everyone as part of the charge.