Past service consideration - Regd

Dear Sir/mam I work for a government college in Andhra Pradesh. At the time of our recruitment (2012), everyone submitted joining letter accepting the offer for Assistant Professor with AGP Rs. 6000/-. But, later during the CAS (Internal Promotions) everyone started claiming their past service and are trying to add few years of service from the private college services. At the time of recruitment seniority is fixed by the authorities based on the merit list and I was the senior person out of total 5 members that were selected for our department. Because of adding private service to the current government service I am loosing my seniority in the department and I will placed at the last as I did not claim my past service which is not legal. Other people claimed their private service to be added to the government service. We follow UGC regulations for promotions etc., In this connection, I request your guidance in this issue and help me in restoring my seniority in the department.