Understandably, you feel frustrated about the situation, especially if you and other students have followed the rules and these students have not. It's also natural to want to take action to address this unfairness.
If you feel strongly about it, you can bring it to your lecturers again and express your concerns. You could ask them what they plan to do about the situation and whether any action will be taken to address the rule-breaking. However, remember that your lecturers may have already addressed the issue with the students, and there may be limitations to what they can do now.
Suppose you feel the issue needs to be adequately addressed or want to escalate it further. In that case, consider speaking with someone higher up, such as the head of the department or a relevant university authority figure. However, before doing so, gather evidence and specific examples of the rule-breaking to support your case.
Ultimately, deciding whether you want to pursue this further is up to you. If you choose to do so, it's essential to approach the situation calmly and professionally and communicate your concerns clearly and respectfully.
Good luck!