Much like the Galaxy Note 5, the Note 7 appears to have a sticking problem with its S Pen. Users have reported the S Pen can get stuck if you press it in too hard, whereas the Note 5’s problem came from inserting the S Pen the wrong way. The stylus seems to get stuck in the Note 7’s water-tight hole when too much force is used.
When trying to remove the S Pen, it’s best to avoid pressing on it any more since doing so can make things worse. Instead, some users have found gently pushing up the S Pen with a pin or needle can get it out.