On page 2 of your invoice you can see how the costs are broken down. What does the individual connection statement say?

Grundgebühren 32,99 €
Verbindungen & Services 59,42 €
Vergünstigungen / Guthaben -16,50 €

This doesn’t make any sense because it’s a CIM card contract and I have already paied the fees on February !!!

What does the individual connection statement say?

This one is for the month of Oktober and it’s still too much because I used to pay arround 17 euros 

Grundgebühren 32,99 €
Verbindungen & Services 14,11 €
Vergünstigungen / Guthaben -21,50 €
Rechnungsbetrag
(davon enthaltene MwSt. 4,09 €)
25,60 €

What do you mean by the individual connection statement ?

you used mobile data outside the EU. where have you been?

I have been in Tunisia but my CIM card was always in flight mode so I didn’t use the CIM card there. 

Flight mode? But that cannot be true, otherwise there would have been no calculation.

What about the extra charges on the month of Oktober ? I didn’t go anywhere outside Germany ?

I’m sure I used the flight mode ! Maybe when I landed , there were some couple of minutes without the flight mode . That can cost 40 euros ? Crazy !!!

Hello @ChaimaElb 
I apologize that we haven't replied here yet and that your question seems to have gone unanswered. That was not our intention. Bumer has already given you good support here 
Unfortunately, using data outside the EU can be very costly. We have summarized a lot of information about this in an article. If you have any further questions, please feel free to contact us at any time.
Best regards

Kathi