Hi Cindy, I wouldn't even go one more week. This instructor is not using motivational methods at all and punching a dog in the nose is not acceptable. You can teach good manners for treats by having Nicco sit in front of you with the treat in a closed fist, do not offer the fist nor move it. You just hold your fist in front of him and brace yourself for some nibbling and chewing and poking at your fist. Do not retract your fist nor speak to him, the very second he sits back and doesn't touch your fist you open your hand flat and tell him "take it". Repeat a few times and extend his wait time and at some point he will glance at you and you reward by telling him to "take it". You should also be teaching him "leave it" and this is done by having a treat under your foot and pivoting your foot off the treat and telling him "leave it" the treat is only exposed for a second and quickly covered with your foot if he moves to take it. The second he looks at your foot and then looks towards you tell him to "take it" while pointing at the treat. These two methods will soon teach him that you are the dispensing machine and there is an order in which he gains the food or attention. Sitting nicely in front and waiting:-) If he is still grabbing like a shark take a small soft treat and hold between your thumb and forefinger and when he goes to snatch get in there with the treat and press onto the roof of his mouth, he will likely back off as if he has something stuck and think about his approach. It is an old method of flicking the nose when baiting to prevent the dog eating the handler's fingers but it is a long way from punching on the nose. I think your trainer would probably potty train a kid by sticking their head down the toilet!!
Definately find yourself a more experienced and up to date trainer and you may find someone on the Association of Pet Dog Trainers that has a website site. Rose T.