What happens when a need arises for me to buy Aavaz for my 2nd or 3rd caller. In this case how will I get charged.

Yes. We charge on pro rata basis till the end of the billing cycle. For example: if you buy Aavaz for your 1st caller on 1st of the month. The billing cycle starts & we charge you from 1st till 31st (end of the month). Now suppose if you buy Aavaz for your 2nd telecaller on 16th of the same month. We charge you for remaining days for the 2nd telecaller. It means that you will be charged from 16th till 31st (end of the month) only.