Service rules

Hello Sir, In 2010 punjab state electricity department is diveided/unbundled into two corporations PSPCL and PSTCL. All the employess of punjab state electricity board become the employees of PSPCL. and some of them are transferred/deputed/secondment to PSTCL as the rule of " as on where it basis" having the common senority among all. Both corporations/govt decided that all new recruitment will be done by PSPCL then some of them will deputed to PSTCL with common senoirty. but lator on due to the disputes of the managemnt of PSPCL/PSTCL both corporations decided/start recruitment by their own. PSPCL is mother body among both corporations. PSPCL has transferred/deputed employees of punjab state electricity board( recruited before 2010) to PSTCL and all the post of PSTCL are filled. Now pspcl is promoting their own recurited employess on the vacant post. on the other hand PSTCL is not doing promotion of thier own recurited employess( recruited before PSPCL) because of having no vacancy. please suggest the procedure/method to be adopted by PSTCL employess for their promotion.