When did he say that?
Cruz hardly spent any money in Iowa. Ted Cruz spent just $580K in New Hampshire vs a massive $32M for Jeb Bush. Cruz hardly made any effort in New Hampshire.
You can look at his concession speech for the most recent example, where Cruz claimed that his 3rd (or 4th) place win was a victory for the "conservative grass roots" which enabled him to "beat expectations." Yet Trump still won the conservative vote in New Hampshire.
Cruz's team has been talking about how many doors they've knocked on "thousands and thousands!" and their "non stop phone calls" they've been making. All of that ground game, however, didn't save Saint Rafael.
A primary is very different from a caucus, especially the one in Iowa where people were freaking writing on green slips of paper who they wanted and tossing it into a basket, where anyone could do so 5, or 10, or 20 times.