"Then we will contact a rescue centre and also inform them of this man"
As an aside to your plan, feelinghorrible, why don't you contact the veterinary practice that vaccinated/microchipped the puppy.
You can alert them to the problem (that this and other breeds are being puppy-farmed via that sellers address) and you may be able to get the breeders details, as it is the breeder who must microchip (although I don't think you will, already there are huge scams round this).
The veterinary practice may also be able to advise you, as may the Animal Inspector from your local council (in any case, the animal inspector should want to know about puppy-farm selling happening in their area).
First thing you should do, though, is calm down. You are having a horrible experience, but really it sounds as if your son is safe (as long as you don't allow him to interact with the puppy), the puppy is safe, and you are safe ... so stop panicking. It doesn't all have to be done yesterday
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You've already made one mistake, if you go at it like a bull at a gate, you will make another. So contact all the right people for advice (please do check on here about your sources of advice, for example not all 'rescues' are the right source of advice), and take plenty of time to think it through. Do not rush to shunt this puppy out of your house in hours and days, (as long as your son is okay) please take the time to make sure the next move is the right move.
I'm sorry this has happened.