If the dog is "Not as described" then you almost certainly have a claim under The Sale of Goods Act 1979.
Some form of receipt or other paperwork giving a description of the dog would be beneficial as any word of mouth description would possibly be denied by the breeder.
You certainly don't want to give the dog back to the breeder in exchange for a refund so I'd suggest that your best course of action would be to highlight the facts to your local council, trading standards etc., and ask that the breeder be checked to ensure that any licensing conditions are being complied with. You may also wish to register your opposition to the granting of any licence renewals or extensions to that particular breeder and make your feelings known to local councillors, MPs and animal welfare charities.
Basically become a bit of a thorn in the breeder's side by getting the various authorities to act on your behalf.
Wishing you every success in your endeavours and, if you do succeed, I'll be right there cheering with the other COL members
Bob.