I think idea is the best network in delhi ncr . As I am using it from last 4 years . I am very much satisfied with the services and the billing section .
call quality - call quality is fine but sone time call drop happens which irretates the most.
Charges and billing - as I am a postpaid user so I am experiancing good plans. plans are better then any other network provider.
Internet - in my area , truly IDEA 3G is the best . once I tested airtel 4G's speed it came to be around 8 Mbps vs my idea 3G which came to be around 13 Mbps.
customer care - customer services are ok ok . as sometimes they make error in my bill but after they easly accept the errors and solve it .