Airtel — no network on 3g mode

Address:

Patna, Bihar, 800004

I'm having data pack.. But i want to use it on 3g mode at 3g speed but whenever i switch to 3gmode then there is no network on my phone i can only use 2g which is of no use for me... I want you to fix my problem of the 3g because... I dont want to waste my money and also whether i use any network mode but there is always a network problem... Suddenly at ground floor.. Or public places the network disappears... There is never good network signals... So please.. Take my problem seriously.. Other wise then i will have to quit airtel