Omaxe trying to extract more moneythrough unlawful means for possession of flat in Omaxe Grandwood,Noida

Myself Md. Zeyauddin had purchased a flat in Omaxe Grandwood (Flat No 705,Seventh floor Alpine-C at situated at Sector -93 B of Noida(U.P.)).
I have received the offer for possession of the above said flat vide letter OBPL/N93B/1077 dated 18th June 2011 from Omaxe.
I would like to draw your attention towards an anomaly between the value of the flat as per the Statement of Account attached with the letter offering possession of flat vide letter OBPL/N93B/1077 dated 18th June 2011 and the Allotment letter of the flat which issued in May 2010/Intimation of due installments letter dated 15th Feb 2011/endorsement letter addressed to HDFC Ltd Dated 20th April 2011 allowing HDFC to mortgage the property.
As per the Statement of Account attached with your letter OBPL/N93B/1077,total value of the flat has been stated as Rs. 4767240/- whereas as per the Allotment letter/Intimation of due installments letter dated 15th Feb 2011/endorsement letter addressed to HDFC Ltd Dated 20th April 2011,the value of the flat is Rs.4629050/-
Assuming that it is just a typographical mistake, I e-mailed Omaxe to correct this anomaly. Though I am yet to receive a written reply from them, verbally they have informed that they are loading an additional amount of Rs. 1.11 Lakhs because my flat is a park facing location. I would like to draw your attention that as per Allotment letter of the flat issued in May 2010, my flat is not a park facing location and hence they had not charged anything under that head during the time of allotment. T he same thing can be endorsed through latest statements as recent as April 2011 issued by Omaxe during resale process of the flat wherein Omaxe has maintained the price of the flat at Rs.4629050/. Now all of a sudden they have realized that flat No 705 is park facing location and liable to pay preferential location charges.
This is unwarranted and against the sanctity of a contract and a huge and unplanned burden on me.
Through you I would request Omaxe to stop harassing with such unlawful means.