Some decision require the vote or agreement of the management committee (the people you voted for to be your representatives). There are many decisions that they can make themselves without needing to notify the other owners/residents.
On the next level is the Strata Management Company. These are the people that your
condo pays to 'Manage' the
property. Sometimes they do everything including security, making pass keys, gardening, cleaning etc. Sometimes your management committee contracts these out separately.
What you need to do is find out where the decision was made and then appeal directly to the relevant person - the management committee or the Managers. I would have thought this would have been a decision made by the management committee who would have instructed the property managers to implement it.
It is unlikely, in my experience that they will reverse the decision for more security - they obviously saw it as an issue. However, you may be able to change the way it is implemented. It may be a matter of a different type of locking mechanism, a lighter gate etc
Management often have rules about deliveries on weekends. This is usually to stop people from getting large deliveries or moving in on days when people are trying to have quiet enjoyment of the facilities (and when most residents are likely to be home and trying to use the lifts etc). Most larger
condos ban such deliveries on Sat pm and Sundays. I think they reason that as many people have home help, the deliveries should be arranged in business hours. It is amazing how it is always assumed that there will be someone home all the time - especially when arranging a delivery!
But grocery deliveries are usually not stopped. I would also assume this would be against public policy to stop these deliveries. In times such as SARS and the recent haze, we were encouraged to get home delivery and the govt would want to ensure that these systems are working well in case of an emergency. So you could argue this with your condo manager.
But get them to carefully check the bylaws about what sort of deliveries can be stopped - who knows if they say all deliveries, even taxis could be stopped!