When someone says hijacking a meeting, it usually means that someone has made the meeting all about his/her agenda.
One time, I was invited to a meeting to talk about "ABC", but they only discussed ABC for the first 5 minutes, then they all switched to talking about something else. I was told we will discuss "ABC" which I prepared before I met with them, but from the start it appeared that they had no intention of talking about that. I also realized that the original agenda wasn't not what they were interested in discussing, so I guess word I am looking for is that I got bamboozled in the meeting or something?
I would always describe that to my boss/peers as "I got sideswiped in the meeting". I googled, and it's not used that way, so I guess somehow I made up that term and everyone understood what I meant anyway. Is there a term for this experience?