Airtel — Deduction for Data Usage

I have activated Airtel 3G Data pack (197) with a good 30 MB of Data available. Suddenly, the balance was deducted from INR 238 to INR 88. When I contacted the Customer Care officials, they informed that the balance was deducted as I have exceeded the data usage. When inquired why the money was deducted with data usage balance still left, they said it won't be considered as that is a minimum data balance, and the money will only be deduted from Main balance. And then the customer care official informed that the money would be credited within 4 hours. I need to know certain things clear: 1) Why the balance is deducted in first place even when there is 30 MB left in the account. 2) I pay 197 RS for 1.25 GB. But it was said that 30 MB will not be considered and the balance would be deducted only from main balance. If so, why do they charge for 1.25 GB. They should only charge for 1.25 GB - 30 MB. 3) INR 150 was deducted for me and i was said it would be credited in 4 hours. What could be done in times of emergencies? Do they expect us to call Airtel 52141 and get loan talktime for calling the customer care for Complaints. This is poor customer service from Airtel and i should say Airtel is teh Worst Mobile service Provider in India. This is absolute Cheating.