Passport surrendered-but don't have acknowledgement receipt

I have applied for renewal for passport. I have submitted passports I had in my possession. I had applied for passport in August 1999 in City A and had job offer from MNC and joining was in abroad so needed passport. But RPO City A did issue me passport till three months before my joining date. I applied again in City B for passport and got passport in April 2000. I was abroad from Aug 2000 till Jan 2002. City A RPO issued passport in Oct 2000(while I was abroad) my father received it and surrendered it in City B but he was not issued any receipt/acknowledgement letter. I am applying for renewal in city C(I had applied for renewal in year 2005 and was issued passport). Now authorities are asking for passport which was surrendered by my father. Passport authorities had asked me to write a letter on plain paper to explain sequence of events which I did. But still my passport application status has not changed. How shall I approach passport authorities? Please help me out. Thanks in advance.