Airtel — my 12 years old no was assigned to someone without notification

Address:

Chandigarh, Punjab, 160039

I have been using my mobile number [protected] for past 12 years plus. I recently was out of station for 8 months. When i inserted the sim it showed inactive, i came to know my number is allocated to some one else. My point is how come in this much short duration you can allocate my number to some one else? This number is update in all my bank accounts, demat, pan detail, aadhaar account. My privacy is at risk as all the sms (Verification code, otp, urn) still goes to this number and i am fully prone to fraud as well because of exposed information. How irresponsibly my 10 years old number was allocated to some one else. After this long service i did not expect airtel to act so irresponsible which put mt at very high risk. Kindly take this matter urgently and give me chance to re activate my number. Thanks & regards, Sandeep