Airtel — ecs not done this time why ?

Address:

380050

Sir,
I am Tejas J Thakkar, my mobile no. is [protected] . for the last so many yerars my Airtel bill is ecs from my bank account. but this time it was not done yet. from your side I received payment reminders so I contact to bank but they said there is no problem in their system and inquire in Airtel. kindly let me know why ecs not done yet ?