How to disable data on Lumia 930?

[Windows Central Question]

Hello! I've turned off data connection and set don't use cellular data for limited Wi-Fi connectivity in cellular+SIM, but even then my phone is using mobile data and this has cost me a lot of money. Am I missing something or my system is just broken?

 

[pankaj981]

Interesting. Turning off data under cellular+settings has always worked for me. Is there a way to validate that mobile data is still being used?