The fact that your breeder is not taking responsibility for selling you this puppy and now will not take him back speaks volumes for the breeder. Reputable breeders take the responsibly of selling a puppy very seriously and many have it written into their contract that if the buyer is not able or willing to proved a home they will take the dog back into their home. The other issue that I see with this situation is that the breeder was not honest with you regarding the size of your puppy which has now caused you to want to rehome him immediately. Poor breeding practices IMHO.
My suggestion is to make certain that you do your homework regarding who you chose as a breeder in the future. It is obvious that this breeders actions is both irresponsible and untruthful just to make a sale.
Please be very cautions with the rehome this puppy to as this is a huge responsibly and your choices now will affect the life of this puppy for many years to come. Good luck!
__________________ “Never argue with a fool, onlookers may not be able to tell the difference.”  Mark Twain |