Conract employee(workman) in psu more than 9 years need promotion

I have joined a PSU as a contract employee for the period of five years in 2010. they offer me the job with training for 1 and 1/2 years and consolidated stipend, after successful completion of training they gave me regular scale and other fringe benefit like a regular employee which is mentioned in my offer letter and then i have completed my probation period (6 month ). But after 4 and 1/2 years of my service they didn't promote me. I have got wages revision 2 time as a regular employee. After 5 years they gave me extension letter for 3 month and then 6 month and it's continue in every 6 month and now they stopped the extension letter from last 1 year, now i am continuing my job without extension letter. I am not Sure about my job security and carrier growth also. guide me please.