Airtel — my 2007 airtel 999 lifetime sim deactivate

Dear sir, i am a airtel prepaid castomar last 11 years. My airtel no are [protected]. But now the sim card have drop tower last 6 month. When i got my nearly airtel store durgapur city center west bengal. The store representative says that no not ur name, and also says this is kolkata cerkel no. So u don't have any options.
Now sir i request to you that no i used long time i[censored]r falt any changes of customer name so what can my responsibility or ur. Because when i purchased the no i have submitted my photo & voter i. D. So please sir necessary action about this matter, as early as possible.
Anup kumar das.
98, ram krishna pally,
D. S. P - maingate
Durgapur - 713203
My no are - [protected]
Mail id - [protected]@gmail.com