Normally my monthly mobile bill (GSM) from a Regional Wireless Carrier comes to about 500 INR (~12 $), since I don't have much of long distance calling to be done. My friends used to say that the telco (Airtel Chennai India) is famous of malicious practices and incorrect billign but till date I have not encountered such.
While casually checking for the unbilled amount yesterday, it turned about 9930 INR (~220 $) and the CallCenter in India was not able to provide a suitable solution and was just telling 'No information available')
I have raised a support request to investigate this but I have a couple of more technical and security related queries which
I would like to get a first hand information on:
(*) In Landlines in India it is possible from the Telephone Exchange that guys used to illegally tap the long distance lines and charge to your telephone account. I would like to know whether GSM mobiles are vulnerable to any similar issues. How to remedy this from customer end, if telco guys are lethargic.
(*) Would it be possible for duplicate SIM cards to operate concurrently on a single number?
( Just want to verify the possibility, no instructions for "how to" )