doublebooked

A term used by someone to get out of a commitment at the last minute due to ignorance, lack of communication or being strong-armed by another individual. People who use doublebooked as an excuse for such an act usually try to lay blame on anyone but themselves, such as a family member or friend, instead of taking responsibility for their disappointing behavior.

He told the group of friends that we was doublebooked two days before the concert, even though it had been planned for nearly a year.