Breach of Contract or Obligation Matters

Hello po sa lahat. I am seeking a legal advice before i proceed with NLRC. I am currently working in this company its was sold twice (buy out) by another company. Now yung contract namin is still from the first company. where all our benefits are clearly stipulated and signed by us and the management. The problem is that this second company who bought us told us that the length of our tenure from the first company is carried over but things get complicated yung 2nd company who bought us sold us again.

As far as i know once you buy a company you are buying all of its assets and employees together with their contracts right? now this third company do not honor this tenure of all the employees as they were saying that the 2nd company did not funded the tenure and retirement benefits. This new company of ours would like to sign an addendum which stating of a new term of benefits and retirement na hindi favorable sa lahat. It's because dinidisregard na yung tenures namin instead back to 0 stating from the day 1 na binili kami.

The question is tama po ba ang ginagawa nila na hindi i honor yung tenures namin and benefits from the previous company? at saka po wala pa po kami bagong contract instead the old one parin ang hawak namin lahat.

Salamat po sa mga sasagot.