I think I have been charged incorrectly.

call13434 calls are subject to a connection fee of 5ct. A 10 minute call to a destination charged at 2ct per minute will therefore cost 5ct connection + 20ct call charges = 25ct.
Also bear in mind that you may have called an international mobile number without realising. Please listen carefully to the free tariff message played before each call you make. The tariff message is the exact rate you will be charged plus the 5ct connection fee. This tariff message is free of charge, therefore if you hang up before your call is connected, you will not be charged a cents.