It is better the Society engages a local prudent Lawyer and get a case filed against the Hawkers making Municipality also a party for not taking action. Problem is that Courts are quite liberal, I am afraid too liberal, in granting Stay Orders in any case till further orders. That may happen in your case too once a case is filed. So discuss all the pros and cons of taking legal action. Unfortunately, for a law-abiding citizen, the options are quite limited.
The issue you have taken up is not in your individual interest and for the welfare of residents, particularly during COVID pandemic time. You are alone and have to take up a fight against four hawkers and those unsocial elements that are encouraging such activities and fight it out with your own cost/expenses. Please consider the risks involved and form a group and collectively make a complaint about trespass to local PS as even hawkers need a license. Peace is important in individual life and in the name of interest, one can not waste time, energy and expenses, think practically.