Vodafone India — fraudulent charges on mobile data during international roaming

I activated international roaming before i left for a travel to the us and immediately after reaching there i bought a local sim and never used the india vodafone sim. I suddenly got a message on the 2nd day of my visit that i have an unbilled amount of 5000. I immediately disconnected the data services from the phone to be safe. Though i had never used any of it. Later they disconnected my services and i did not bother about it then since i had a local us sim. Upon return to india i paid 1500 rs. Since the amount was over my credit limit of 4000. (Which also i think has suddenly been increased) i was shocked to see my data bill close 19, 000 after a few days. For absolutely no usage of data i keep getting this ever increasing bill. Also now they have deactivated my outgoing calls. The customer care refuses to listen my concern and won't even connect me to a senior executive. All they want right now is payment of 8000 to continue services. This will continue untill i have paid all the wrongly billed 19000 (Or even more considering their bill keeps increasing day by day)
Thoroughly cheated. I don't know what to do about it. I need to file a complaint against vodafone