Urgh, was I lied to?
 

I requested an exit row seat and was told there were none left. Ok, got an aisle seat instead, no biggie. However, as the plane flew I notice an empty exit row seat....

So... was I lied to or a screw up in the computer system?

You may have been lied to.

Or the person previously occupying that empty seat was upgraded, or cancel the reservation, or no-show, etc.

Or you did not have elite status, and the agent said that none is available to a person without elite status.

Or there could have been a screw-up in the computer system too, but of all the possibilities, this seems unlikely.

I am not sure how useful it is for you to post such a question here. Clearly there are many possible explanations, and no one here can confirm any one of them.

If you really want to find out, best way is to call or write CX and ask about it.

An airline employee made up an excuse rather than figure out how to do their job properly? No, that could never happen...

CX has given me all sorts of excuses as to why I can't book an exit row seat. Best option is just to try someone else.

You could request again in the gate. Normally the success rate is quite high to change seat.