That is definitely not a Lab or a Corgi. Neither of them come in brindle! It is most likely an American Pit Bull Terrier puppy, like this one:
The only other breeds that come in brindle also have wrinkles or markings on their face from birth, like the Boxer, Cane Corso, and Bull Mastiff. However, there is not a trace of Corgi in there. Corgis are very small and have narrow, tapered snouts. Hounds also have a distinctive tapering of the muzzle. It is possible that this is a Pit Bull mixed with Labrador, since some lines do have brick or square shaped heads. However, the brindle coloration, square-shaped head, and absence of wrinkles or other markings is a clear indication of Pit Bull heritage.
A word of warning: it looks like the one you've got is much younger than 8 weeks old. I think that you should have done a lot more research on the breeder and the breed you were getting. This puppy appears to be 5-6 weeks at the most. Because Pit Bulls are Terriers and have a tendency to become dog aggressive, it is important that you get them at 8 weeks, to allow them to develop good social skills with their litter mates. This puppy will need a lot of proper socialization with other dogs to prevent dog aggression from developing or getting out of control as the dog gets older. I would highly advise that you sign him up for Puppy Training and Socialization the minute he has his second set of shots.
You can learn more about the American Pit Bull Terrier here and here.