If your community rules are being broken, there's a problem.
Don't just respond to it, resolve it. Keep track of whether it's the same rules being broken, or if it's the same members breaking the rules. The difference is pretty important.
Dealing with repeat offenders
If it's the same members breaking the rules you need to nullify or remove them. There are various tactics here.
The problem here is it doesn't scale well. You want to quicken the process rather than react to every member. This means you need to develop an intervention to tackle the awareness issue, and then the acceptance issue.
This may involve introducing a simple 3-strikes rule, asking members involved directly to stop breaking the rules or having a wall of shame for members that constantly infringe against the rules. The trick here is to use data to identify the problem, develop and test an intervention, and then spend your time on more important community tasks.
Dealing with repeated violations of the same rules
But what if it's the same rules repeatedly broken?
This is either an awareness problem (they don't know about the rule) or an acceptance problem (they don't agree with the rule).
In this situation we can consider removing/changing the rules (is it really necessary? Is it preventing members from doing something they genuinely want to do?).
If it's an awareness problem, you need to publicize the rule. Send an e-mal to all members, post a sticky thread or strictly enforce it for a short period of time.
But this doesn't scale well. New members still wouldn't be aware of it.
Therefore, develop a a welcome guide which lets members knew how to behave. The trick here isto write in an entertaining/useful way that it gets read.
It has to tell members what they should be doing, not what they shouldn't. Long lists of guidelines are always ignored. Long guidelines don't change behaviour.
If it's an acceptance problem, then invite feedback from the community on the rule. Or better, invite the community to work on a joint constitution that defines the rules.
The goal here is to use the data you have available to pinpoint the problem and then introduce an intervention that will optimize your time. You have a choice to either continually react to the same problem, or try to resolve it.