delinquent payment in sss

I was approved on 15k loan and received 13.350k because interest is being deducted last February 2010. My monthly amortization started April 2010. I checked my payments on the net which should be finished last March 2012 but unfortunately I’m still paying for it. Upon checking the status of my payments last 2011 I found out that I was only deducted half for monthly payment and I was noted as delinquent payer so I immediately informed the HRD and asked for correct deduction. It was not immediately implemented and after a month before they corrected the deduction. For 2 months I'm deducted for the correct monthly payment and the next month I was deducted again half of the monthly payment and the succeeding months I was deducted again the correct amount. I am planning for filing a loan and as I checked I still had to pay 7,400.00 to be able to be approved for another loan. I earned interest and penalty for almost 4,000.00 aside from the original interest and it is still increasing everyday.
a. Do I have to shoulder that even if it is not my fault?
b. What are the legal actions that should be charge to HRD?
c. I am not the only one who experienced the same in the company but they do nothing about it and shoulder the interest.
d. What is the best thing to do?
Thanks!!