Might want to look at the Private Agencies Act which requires any agency engaged in providing security services to be appropriately licensed. If the management and company is comprised of the residents, they can argue that they're providing their own private security but if it also extends to people who are NOT part of the program, then it may be construed as being provision of such security services to 'other persons'. Has the Resident Committee properly registered with RoS?
I have a feeling there may be no proper laws on these, I remember quite clearly just recently there were announcement that there were no proper laws on the regulation of gated communities which therefore allowed construction vehicles to pass through the 'gated' community to reach a construction site not related to the gated community.
Usually for strata title cases, there's a management corporation formed upon the issuance of strata title and they govern the 'common property'. Here it's a bit different since there's no strata title involved. Have you signed any Deed of Covenants or Management Agreement when you purchased the property that governs the use of the common facilities provided in the gated community? What is the agreement in relation to the maintenance of the 'gates' and walls? Are there any further provisions in there that would allow them to impose other charges? If there isn't, I'm not sure how they can compel you to pay.
Note that your local authorities ordinances and land issues are governed by your own Sabah legislation so only a Sabah lawyer familiar with this would be able to comment on these conclusively.