Why my mobile is using mobile data although my data is disable

[AC Question]

Hi I am using Sony xperia XA dual sim. I got this mobile a month back. Since yesterday m getting the message from my network career regarding the data usage within a minute everytime. I am just fed up of all this. M getting msgs in a minute. Means 60 msgs in a hour. Although m using wifi and not mobile data. This caused my mobile heating. M using marshmallow. After removing SIM 1 i arrived at conclusion that this was not career company msgs, and because of mobile software. finally I have reset my mobile.Please suggest me the solution.

 

[ManiacJoe]

SMS messages are transmitted using only mobile data, not wifi.
I would expect that you could turn off the mobile data, but that would also prevent the receiving of SMS messages.

What version of Android?
What carrier?