Please dont get cheated by Matrix SIM card. Their charges are very high. The duration of the call whichever you make the is not correct.
I recently took one SIM card for Western Europe. For 9 days I was charged Rs.6984.19/-.
They make you swipe the Credit card for security purpose. This is the first trap. The call charges automatically goes from your credit card. You have no control.
Buying a local SIM from your country of visit is much much cheaper. You can select differnt cards as per your need. ( To make more International Calls/ Local Calls).
Please DO NOT GET CHEATED BY MATRIX SIM CARD.
Sadashivan