Well there are a few things to say about this...
>we felt that it would be perfect to have pups from the same breeder as they could socialise and grow up together.
I wouldn't really recommend it, to be honest. What happens when siblings spend a lot of time together (or really any two puppies of about the same age), is exactly what happens when people buy two puppies at once - the risk of littermate syndrome. This manifests in various ways depending on the circumstances, but with 2 Labs together I would foresee a lot of rough play, a lot of puppies getting excessively into 'using' another dog as that source of play (regardless of what the other dog wants) and losing focus on you as the handler. If you put them on leash to stop the play, then you have 2 frustrated puppies that just want to continue slobbering on each other's necks until their tongues touch the ground. Much better for you to get pups with some age difference really... That way they can bond with you, their people, and look to you for fun and reinforcers and not learn that other dogs are the bomb.
>they would not be KC registered and would this be a problem (reason for not registered was that the Sire was not a KC registered dog therefore pups would not be registered). We agreed this is not important to us as the pups would be family dogs not show or working dogs.
You haven't mentioned anything about health testing. If the dog is KC registered, you can verify health test results using the KC's website. If you are just relying on what the breeder says, they can easily tell porkies. And you'd be wondering - why is the sire not KC registered? Most people will KC register a dog if they can, so the only reason would be:His mum was older than 8yo when she had the pups. The sire is too inbred (ie the result of incredibly close in-breeding - brother sister, for eg). Or he's not even a pedigree. You have no proof the dog is even a Labrador! Perhaps the bitch got caught by an unknown dog, and the stud looks like a Lab - but maybe the pups he throws won't look like Labs... That's how genetics works.
Frankly if you care enough about a breed to specifically want that breed, then be sure to get a KC registered dog - otherwise you might be getting anything. Don't just lower your standards to get a pup - any pup - right now during the coronavirus when things have gone crazy. You're going to own this dog for upwards of 12 years...
£750 is pretty expensive for a potentially crossbred dog which could be anything, to be honest...
>We are devastated, but have some niggling doubts as the breeders name and details have suddenly dissapeared off the Kennel club site, we have had no repy to our email asking what happened either.
I'm sure you're aware of the demand for puppies at the moment. If a breeder has just lost an entire litter they will be devastated and the last thing they want is to be fielding endless calls from the public asking if they have any puppies...
But I'm not really sure why a breeder listed on the KC website would be advertising a litter with a non-KC registered dog as sire, to be honest?
As for what happened - they died or were born dead. What more do you need to know? I'm not sure why you think this is suspicious. It is awful and traumatic to whelp an entire litter of dead puppies and then have the bitch grieving for them as well, full of milk - the last thing they are going to want to do is to relive what happened over and over to explain it to people on their puppy list.
>My concern is that this person has our names and addresses which were given for chipping, so would you consider it completely legit to give our sort code and acc number for the refund in light of that ??
What do you think they are going to do with your name and address? I think you'd be surprised to know how easily it is to get hold of someone's name and address - most of them are there in the phone book or online for the looking! No one can do anything with your sort and account number other than give you money, which presumably is what you want?
>How often does a dog have a complete litter stillborn on the due date ?? I'm a ''human'' midwife so am fully au fait with possible causes of stillbirths but wondering if it is usual for a whole litter to be stillborn ?
Yes, very possible. If the first puppy out blocked the exit route and vet help wasn't sought fast enough, the rest of the puppies will die before they can get out. If a bitch goes into inertia there are no external signs and everything looks fine - but the pups are all dead because she went over.
You seem to be looking for someone to blame when there is no one to blame and the breeder has traumatically lost a litter of puppies and wants to move on and draw a line under things as quickly as possible, being very responsible in seeking to return deposits.