She's a lovely puppy, but there are a number of things about her that indicate she's probably not a full Golden (coat, color, pigment, eyes, head, ears, etc.). White mismarks are very possible on a GR, most commonly on the feet, chest, and head, but I've never heard of a brindle coat nor the brownish tint to your pup.
There's also no such thing as an Italian GR, unless you mean a GR who lives in Italy.
You were definitely lied to by the person who sold you the dog. Did this person claim AKC affiliation or any other kind of membership or affiliation with a purebred dog group or a Golden Retriever club?
Obviously, you won't give up your dog now that you have her, but you may be entitled to get some or all of your money back from this person, and at the very least they should be reported to whatever organizations they claim to be a member of. You can also post the breeder's kennel name here so others can find it and avoid being defrauded like you were.