Tata Indicom Non-Stop Mobile

I took two Tata Indicom Non-Stop Mobile in october 2005.
I got both mobiles recharged when my balance was Rs.30/-
Initially there was no charge for incoming and outgoing calls between both Tata Mobiles perhaps upto march-07.
Now this is being charged and my balance is reducing on every outgoing calls between both Tata Mobiles.
Please rectify the mistake and credit the amount charged on both Mobiles for outgoing calls between both Tata Mobiles.
S.K.Agarwal
9/7/07
shaile003@yahoo.com