I subscribed to Reliance mobile in the year 2003

I subscribed to Reliance mobile in the year 2003(Mobile no. 9312701043)under Dhirubahi Pioneer Offer. At the time of subscription It was informed that after three years monthly rent will not be charged and only user charges will be payable. Now the Reliance has backed out.
I have been regularly paying my bills before due dates which can be verified from the records and payment for the month of June 2006 was deposited by cheque at Reliance Web world at L Block, Connaught Place near Narulas. I received a reminder from Reliance for payment of said bill and informed them that payment stands made. The caller was rude told me that I have not made the payment. I told her to check the records, but she refused to oblige me and insisited that I should pay immediately. My cocerns:
1. Why orginal offer terms under Dhirubhai Ambani Offer plan have been altered by Reliance?
2. Why Reliance Web Centre do not issue acknowledgement of payment received and forced the subscriber to deposit the same in drp boxes?
3. Who is reponsible if Reliance misplace the cheque deposited?
4. I hav erecd communication from Ptiti Sing, Head Customer Service on which the address of the office from which this originated is not mentioned and as a result one can not approach them.
Is there anybody to check such mal=practices being carried out by Reliance.
Regards,
Ashok Anand
A 203, Meera Bagh
New Delhi 11 00 87.