Hilf mir zu verstehen, warum es so hoch ist, weil dies meine erste Rechnung ist

Schaue in deinen Einzelverbindungsnachweis, dort stehen die Verbindungen. Wahrscheinlich Anrufe ins Ausland.

 I had no idea that international calls are charged, i believed like with lebara it also had mintues free. I just saw and there were major calls, can i call them to get bill reduced also nobody told me about to not make international call

​@Manish_Rathore 

Sorry, but it clearly states in your contract details that international calls are charged. And o2 will not reduce the bill.

​@Manish_Rathore I understand, but it won't be possible to reduce the bill. It's always important to find out the exact tariff details. I'm sorry to hear that you assumed we offered free minutes. So you've had a look at your contract details and found the costs for international calls?