Airtel — wifi disconnected 3+ months ago but refund not being processed

Address: Bangalore, Karnataka, 560103

I had a excess 9k in my account during disconnect out of which airtel confirmed to refund 7.5k (Don't know why less).
Its been more then 1 month they keep on telling me its processed and will reflect in account in 3 days but nothing happens. I cannot even find a refund initiated record on online refund website and [protected]@airtel.in sends standard reply everytime when asked about status with future dates and promise.