Dear Avani,
It appears that you have perceived that senior person as dreadful ogre. There was no need to do so. If he sent you offensive messages, then all that was required to approach to the Labour Office of your area and explain your problem to the Labour Officer (LO). Labour Department takes complaints of this kind very seriously. Possibly Asst Labour Commissioner (ALC) or Dy Labour Commissioner (DLC) would have sent letter to your MD. On receipt of letter, your MD would have come running around. Some QC Manager, is small fry for them.
Bangalore has large number of MNCs. These big shots developed cold feet when labour department had sent them notices. None of the MNC, Indian or otherwise, has dared to ignore notice from the labour department.
Even now also you can approach Labour Office. Make sure that the complaint is genuine and you have sufficient material evidence. However, your resignation has weakened your case at least partially, if not fully, The other option is to approach NCW.
Thanks,
Dinesh Divekar