That may be the way it is supposed to work, but it did not in these two.. I found the charges on my bill today. I know I didn't have these messages, so I checked my wife's phone. The text were there and had NEVER been open or acknowledged. My wife will not open a text or email without knowing who they are from.. good security, I thought....I opened them both and they gave me the option to "STOP" the monthly bill.. A little late don't you think"!! I was billed before the text were ever opened or acknowledged !!! Therefore, the system is NOT working the way you say it is supposed to and we are being billed without our knowledge or permission.. Now What !!!..