@Carmenesque What mobile you exactly use? 

@Joe Doe iPhone 7. I was charged today as well….

@Carmenesque Stupid question. Did you switch off mobile data in your IPhone 7? Can you switch to GSM only mode for testing?

Yes, the data is switched off all the time. I couldn't find GSM mode, is it the same as airplane mode?

@Carmenesque disable LTE/4G please

https://support.apple.com/guide/iphone/view-or-change-cellular-settings-iph3dd5f213/ios

My only option is to set it to 3G. Does that work as well?

@Carmenesque yes.

Okay, done. So this should prevent further charges?

@Carmenesque Book my Prepaid Basic or let deactivate mobile data over hotline. With 4G (VolLTE) you must every time have fear that a data session will start.

Sorry that's not really a solution for me. And there is no accidentally starting data session, since I'm 90% of the time at home with WiFi. Both SMS came at a time when I was home, and wasn't even touching my phone, so I didn't turn on LTE or anything. This strange charge happened already several months (or even years) ago, but it happened again now twice so I was wondering if the customer service at o2 can help with this or there's no way to prove that I didn't activate the data. 

Also I occasionally need the 99 cent data (though not recently), so I don't want to deactivate it.

@Carmenesque This is in the moment the only  options that I can provide as a customer. You can wait for an o2 moderator and see what she/he say.

Thank you for your help!

Hi @Carmenesque, 

welcome here in our English Community. Nice to meet you here. 

@Joe Doe already gave you some good suggestions. 

If you do not want to block completely mobile internet, you only have the possibility to switch off data-service on your phone or order a data-pack as @Joe Doe already suggested to you. 

Please be aware of the fact that you have no guarantee if you use WLAN that you do not use mobile internet for a few seconds. If WLAN is a bit unstable for a few seconds, we will continue to charge you with 0,99 € per day. 

How would you like to decide?

Additionally, I topped up the amount for the 2 Surf-Dayflats for you.   

I hope you agree to this solution. 

Loving greetings,

Tobias

Thank you Tobias, that is perfect! Meanwhile I found out how to switch off my Data completely, like Joe_Doe suggested, so all is good! 

Thanks again!

Hello @Carmenesque,

glad to hear it all worked out for you! If you have another question in the future and need an English customer service representative, feel free to come back here to the English o2 community!

Have a nice weekend ahead!

Jessica