Airtel — airtel sim is not working since 25 days

Address:

N-15/105 A Sudamapur, Varanasi, Varanasi, Uttar Pradesh

Dear sir,
I ashwani kumar sonker using airtel sim since 4 years. From last 25 days outgoing and incoming call has been stopped. Without any prior information my sim has been blocked. Many times i contacted to customer care but nothing happened. Several times i gone to airtel store but no action was taken till yet.
This number is very important number because it is linked with the bank and my all the work is badly hampered due to this.
Therefore, i kindly request you to take action on this matter and please start my sim so that my work can be started.
I will be highly obliged of your kindness.