Can you please elaborate on what training you have done with your dog? Have you worked with a trainer? Please be as specific as possible.
Every single thing you want to achieve with your dog can be done with reward based training. A prong is not needed and should NEVER be "popped." Please do not listen to this advice. One of the dangers, beyond physical injury, is that pain can change the "excited" response you're seeing into a fearful and aggressive response. A prong can theoretically be used as an effective and humane tool for many dogs, but in a situation like you're dealing with it wouldn't be training. It would be punishment and management through discomfort and pain and that's not teaching the dog anything except that it's uncomfortable to do certain things at certain times.
If you'd like to share where you're located perhaps we can help you find a trainer in your area.
I agree that training would be the number one and best approach to this. Now that you're at where you're at, what with your Corso's training needs not being met thus far, it will take remediating action to try to get on top of this. I agree with the back-to-basics idea here. For me, hiring a trainer has never been an option due to expense and, well, I just decided from the start to do all my own training. I always start with training the heel. For me it's the foundation.
@Boxergirl , if I may, I'd like to inquire about your assertion that popping a prong collar is a bad idea and could cause injury. That has not been my understanding. It seems to me that probably about 98.5% of people use the prong collar incorrectly, in that they just let the dog pull on it and in so doing deliver itself a correction. The way it's meant to be used is (with the collar high up on the neck, and not being allowed to slip down) that there should not be any tension on the leash/collar, and when the dog puts some tension on it, you give a crisp pop probably accompanied by a command that the dog understands. So a combination of training and perhaps a prong can be effective. It's been my understanding that the prong collar won't inure a dog, and a traditional choker, which has so fallen out of favor (not really for me) is what can theoretically cause damage to the throat.
I've heard several experienced dog owners refer to a prong collar as "power steering for your dog" which unfortunately gives the impression of it being used improperly, but in the case of these people, I don't think so. Me? I have never really used one much, as a prong collar seems to shout to the world "I have a training problem!"
Back to the jumping: As for jumping on you and people you know, I have always recommended simply telling them to put up a knee for the dog's chest to run into. Of course, the person would have to have sufficient health and dexterity. I wouldn't ask grandma to do this. Of course, if you have a particularly driven, spastic dog who loves very much to use their paws (like mine) you might just wind up with their front legs hugging your calf and the problem goes from there – ha!