How can I undo checking the box 'do not show again'?

[forWantOfAUsern]

While turning off mobile data from the notifications drop down, I got the default information message with the checkbox to not display message again. I accidentally checked the box. I want to keep seeing this information however. I've tried deleting stored data, cache, and resetting all app preferences in the settings menu, but to no avail. All I seem to be left with is factory reset but I don't want to lose any important information. I've also looked up a lot of related articles online which also provide no help. How, if there's any way, can I undo this action? I'm using an Xperia Z. Thanks very much.

[_alexdon_ · Accepted solution]

@forWantOfAUsername clear data for phone app under settings - apps - all.

[forWantOfAUsern]

Oh my God!! You genius!! Graçias graçias merci!! Didn't work at first, had to restart phone in order to implement changes. Thanks a million!

[_alexdon_]

@forWantOfAUsername you are welcome.