Counting of past service and pay protection

Respected Sir, I am rani....Sir, I had joined firstly in Chennai Circle, Department of Telecommunication and Information Technology, Govt. of India as a Senior Accountant on deputation basis from a State University, i.e. Arunachal University, Arunachal Pradesh in 2006. In 2007(after 1 and half years, I had been transferred to the Kerala Circle Trivandrum as the same post on deputation, In 2010 I had repatriated to then office in same post. After 1 and half month, I got an offer from the DOTfor joining as Senior Accountant on one time absorption basis,in the same pay scale... as such I had joined in this esteemed department after technical resignation on 13/9/2010 from my office(at the time the university was converted into Rajiv Gandhi Central Univeristy),adopted CPF Rules under CCS Pension Rules 1972. After joining my pay was fixed with my MACP Scale. Then I submitted an option for including me also to the pensionery benefit service within one year. But they had kept it silently. After 10 months the University given me the terminal benefits. After eleven months, the DOT issued me a revised pay fixation memo(pay fixed in initial stage), So I submitted a representation for giving me a chance to refund all the benefits i received from the university with 6 percentage interest to the department or university. But the dot kept it silently and they informed me to recover the overpayment as well as the reducing the pay(it comes me double loss effect)issued me the letter on 12th of the month(at the time of preparing the pay bill