Have you also switched off your Wi-Fi Assist @Patrick_95626? This feature also needs to be disabled to ensure that the phone doesn't connect to mobile data, even if you have turned off mobile data in the settings. Depending on your phone, there may be an option in your settings to control what your apps connect to. I'd suggest you double check to make sure that mobile data is switched off here as our apps are continually running even when we're not using them.
Unfortunately I have disabled all apps and wifi assit connections but there was still a 2 euro on my account today. I wish to have this issue resolved as quickly as possible.,
