He said Texans general manager Rick Smith told him and his agent that Robinson wouldn't be tagged in recent weeks.
"Tagging was out of the question, according to Rick," Robinson told The Associated Press. "I was told that. I just feel betrayed. I'm disappointed that they lied to me."
The move gives Robinson a salary of $9.957 million for 2009, the average of the NFL's five highest-paid cornerbacks.
Other teams can still make an offer to Robinson, but the Texans can match it or receive two first-round draft picks as compensation.
"Dunta is an important part of our team and organization," Smith said in a statement released by the team. "We worked extremely hard to try and get a long-term contract done with him. However, we were unable to reach an agreement. We hope to reach a long-term deal that ensures that Dunta will remain a Houston Texan for years to come."
Robinson learned of his status from reporters who called for interviews about the situation.
Robinson, the 10th player taken in the 2004 draft, started each game in his first three NFL seasons and developed into one of the top young cornerbacks in the league. Injuries have slowed him the past couple seasons.
Though upset about his contract status, Robinson said it won't be difficult remaining with the team.
"I'm still able to play football, and I love my team," he said. "I love playing for the city of Houston. Something somebody does or something somebody says is not going to affect my game in a negative way."
At the end of last season, Robinson said he hoped to finish his career in Houston. Now the 26-year-old isn't sure that's the right move.
"Because of my teammates and because of this city and my family ... I really don't want to leave," he said. "But a situation like this makes it much, much harder to stay."
Copyright 2009 by The Associated Press