Defamation case may not be maintainable in this situation.
The new committee has taken decision to take charge of the association somehow without your support or ignoring you.
They have violated all the norms and rules in this regard.
They are also putting pressure on you through police with their influence.
Actually the police cannot interfere in the affairs of the association.
You can give a complaint against the police excess to the city police commissioner and seek his intervention and relief.
You can even call a press meet to expose the arrogant new committee members who indulge in such activities which outrages the modesty of women by insulting her in public.
Though the legal actions may stretch the issues causing you more sleepless nights this can bring you desired relief.
Alternately, you may just throw away the responsibility on their face and get rid of all such issues which have caused furores in the past and remain peaceful thereon.