Haryana Urban Development Authority [HUDA] — About wrong balance

Address: Sonipat, Haryana, 131301

Dear sir/madam
I have a plot no 890 p in huda sector 7 gohana haryana. I have sent an letter for inquring about balance due dated on 14/feb/2011.in response of your letter i received a letter memo no. 3915 from estate officer stating that your balance of amount rs-18720. After receiving letter, i've submitted rs-21000 through icici bank. Now, i want my balance back (Rs 2280). When i ask for land mortagage of my plot, they showed me a balance of rs-78834 and asked me to pay the balance, only after that i will get land mortagage.
Why this is so?
Note:- pls check the documents attached with it.