How do I report a scam regarding pet delivery to ones door.?

I was on the brink of having a british bull dog puppy delivered to my door from Scotland as the ad on the internet said the dog was alone all day and I could have him for free and that it would be arranged for a pet delivery service to bring the dog to me. However, I have just found several sites with exactly the same photograph of the puppy located all over the UK offering the same service. I think they are getting money/bank details from people for delivery, but do they receive a pet?