The weight discrepancy is not huge and can be easily explained, the first weight might not have been on empty this would easily explain the 44 grams difference.

Personally a 44 grams difference is nothing make a big deal of, I could understand if it was an animal advertised as 600 grams and it was only 256 grams however I doubt I would have an issue with something like this.

As for the others it is possible for a BP to skip a week or two every now and then no biggy (that does not qualify as going of feed to me) especially if fed a bigger prey.

As for feeding record not everyone keeps them, I have received snakes without any records (does not really bother me).

The bottom line those are YOUR snakes and if YOU don’t like them or feel like you were done wrong than talk to the seller.