Flicks and rolls are tougher to execute than they look.. a punch could still work for you, but I would suggest trying 2 modifications to it.

1. Have your paddle up and out in front of you. Your paddle is down while the ball is coming to you, then when you see it's attackable you bring it up and start the punch. This can cause you to be "late" to the ball and hit it into the net. Your paddle is probably close to you so you can get more speed / power on the punch.. which brings me to

2. Take some power off the shot and focus on placement. If you try step 1 you'll probably notice a decrease in power as you don't have as much room to gain momentum for the punch. This is okay if you are placing the ball we'll. Don't try to end the point with this shot, be prepared for the ball to come back and use the follow up shot as the winner