Airtel — unused data balance is deducted.

Address:

New Delhi, Delhi, 110068

My data balance in the prepaid airtel number which i use in my mobile all of a sudden showed the balance as 0, shockingly as i had unused balance of 1.5 gb and my recharge date was on[17 feb 2020]. How can you deduct the unused balance? I need this issue to be addressed and suitable explanation with the balance to be reversed to my account. This has happened to me the 2nd time in the past 2 days which is why i now come to realize that airtel service provider is none better than the rest which they otherwise claim to be.