I have been using Airtel for the last 5 years and never had any issues with the billing till May 2011. From June I was overbilled for no apparent reason and eventually switched to a 512 kbps Unlimited plan (around Rs 500/month) in hope that i won't encounter the issue again. My bill was adjusted every month because of my complaint so i switched to an unlimited plan.
But this month i got a shock when i saw the bill amount to be Rs 2200. I have used around 2 GB which comes under the FUP usage. I have raised the complaint (no: 5396818) but they seem to be taking their own time to resolve this.
I initially thought it could be some software issue in billing but now it looks like Airtel is intentionally overbilling customers to make Profit and probably ripping customers for the 3G spectrum that it bidded.