I would like to suggest that at the first instance you may approach the Labour Inspector Of your area by making a complaint regarding non payment of your legal dues against both the managements. If the matter is not settled by him then asked him to take action for non payment of dues. He will also suggest you the forum befoe which your claim case will lie. In general it is told that all the Labour Officers/ Astt. Labour Commissioners are declared as Controlling Authorities under The Payment Of Gratuity Act,1972 before whom you can file a claim case for non payment of due gratuity.
Hope that to some extend you will solve your problem.