Recognized predefined text will be lowercase, that is not specific to that token.
If you want to use the exact case entered into the "When I say" field, you'd need to retrieve the contents of the field (E.G. using the "{CMDWHENISAY}" token or the WhenISay() method in an inline function), parse and split that, then match it to the recognized text (using a case-insensitive comparison).
Using an inline function for this would likely be the more efficient method.
If you are referring to using the "Set a Text Value" action directly with a token, you'll want to read the documentation on tokens, to gain an understanding of why that cannot work.
This topic may also be of use, in addition to the official documentation:
Variables and tokens summed up