Little Miss - feel so sorry for you in this situation as you are paying your service charges and subsidising other owners who have not bothered to pay their charges.
The Directors of the Management Company are ultimately responsible for putting things right as they are supposed to be running the Company on behalf of the members. They employ a Managing Agent to run the development on a day to day basis but as Directors they are ultimately responsible.
From their point of view, I guess it is difficult to turn things around without funding so they need to pursue non paying members through legal means.
If service charges are not collected then the Management Company will not be able to pay for even the most basic of services e.g paying the electricity bill for lighting.
I think you need to ask the Directors to call an Extraordinary General Meeting and come up with a plan of action to turn things around before it is too late.
It is in everyone's interest to pay the service charges - property prices are maximised, rents are maximised and people who live there will have their quality of life improved.
Best of luck and I hope that you can pull a group together who will turn this around.