builder charged wrong interest for the period before agreement
1 -booked a flat with 10% on 6 may 2010.
2 -builder delayed agreement signing because its papers and layout was not sanctioned. But dont have any prof for it . only verbal communication.
3 - signed an agreement with builder on 7 sep 2010.
4 - In agreement it was written first demand 10% on booking and second demand 10% on 30 day after booking.I protested verbally but builder said that It is standard agreement .. And said that It will not create any problem. I believed the builder.
5 - Got second demand 10%( 30 days after booking written in agreement) on 16 September 2010 described as previous due , paid it by 4 October 2010.
6- Now builder is charging interest for second demand delay .He is saying that it was due from 6 June 2010(30 day after booking written in agreement). But this demand was received on 16 September 2010. And one more thing agreement itself was signed on 7 September 2010.
7- one more thing , I have a brochure which say second demand to be paid on bhomi poojan somewhere in august 2010.
8 - How builder can charge Interest before agreement?
9- Builder himself delayed agreement (don't have written proof)
10- Builder sent the demand letter on 16 September 2010.But expecting to pay it on 30 June 2010 ,the time when agreement was not there.
How I can challenge it.
My only mistake is that I did not protest in writing for the clause " second demand to be paid within 30 day of booking".
Can I still challenge it