Q: How can I still receive a text when everything is off?  Wi-fi is off, cellular is off, EVERYTHING IS OFF. I should be off the radar completely, and yet I still receive a text message.  How is that possible?

So, I'm not a noob when it comes to I-phone.  I haven an iphone 5-c.  I'm very cautious of privacy settings, etc.  99% of the time, I have everything turned off.  No matter what, if I have everything turned off, I will still get a text message.  How is that possible?  I do have I-message turned off, so the only thing that "should" get through would be an SMS message, but if my cellular is turned off, and my wi-fi is off...nothing else turned on....  How in the **** do I still receive a text?  When I have everything turned off, I can't make a call...I can't check my e-mail etc...So, how is this possible?   

Please, help explain!  This is disturbing.