SMART(Relience) mobile service user

Sir I am a SMART(Relience) mobile service user.From very begning they started to harash the customer.We took the connection by giving Rs (750+250)=1000.The call charges were 19 paise for same network,59 paise for any other local mobile and 99 paise for any STD calls.A rs 55 topup was valid for 6 months and talk value was rs.49.Now they suddenly started to cut Rs 1.99 for local calls ,Rs 2.50 for STD by saying that the Rs 250 validity is expired but no such period were mentioned in the booklet oviously there was a * mark.And intrestingly many customer who took connection before me are still getting the old call rates Please help me to restore the previous call charges.
At present I cant change my service provider bcoz my no will change.I am waiting for long awaited no. portability which will helps us greatly,I hope so.
THANKS.
YOURS:
SK. FIROZ QUASIM
16/G REMOUNT ROAD ,
KOLKATA-700027.
MOB. PHON.: +919883150041
Contact Email ID:mdfiroz136@yahoo.com