What have you got?

[Ref_in_Alberta]

FIBA rules are very clear on this - an unsportsmanlike foul must be assessed. It is in the interpretations for Art. 36 Unsportsmanlike Fouls. The case the OP has FIBA interprets the "correct" ruling as the following -

Because the team B player is obviously not makeing any effort to play the ball and an unsportsmanlike advantage is gained by not allowing the game clock to restart. An unsportsmanlike foul must be called without a warning given.

Now having said that, in the case where the ball has left the hands of the team A player and then the foul occurs, this should be judged as a normal personal foul unless the severity of the contact warrants an upgrade to an unsportsmanlike or disqualifying foul.

This is a new interpretation for the rule changes that occurred after the Olympics. And Yes I have had to make this call since my season started.