Hi i am looking for some advice for my sister regarding a badly gone wrong puppy purchase, in private . She is soo upset.

If this is connected to your other post then you probably need to speak to the RSPCA.
Is the puppy unwell?  Is it not the breed it was claimed to be?  Or is it a case of false or missing documents in which case it may be Trading Standards you need.  Or it may be the local licencing authority.  I think you need to give us a little more detail really if you want people to give any advise.