They announced on last January 18, 2013 for their promo launch.
I grab the copy of Smart so here is the example...
Smart bares biggest prepaid trinet offer ‘Unli Call & Text 25’
[18 January 2013] Banking on the sheer size of the combined Smart, Talk ‘N Text, and Sun Cellular subscriber base, wireless leader Smart Communications, Inc. (Smart) is launching its biggest ever and most affordable unlimited offer called ‘Tri-Net Unli Call & Text 25’.
For more information you can follow this Smart Press Releases.