Good behavior of dogs

When our 2 dogs were puppies, we hired a dog trainer to teach them good behavior and also some tricks. The training session was 1 hour for each dog that goes 3 times in a week. After more than 2 months of the training, our puppies looked good. They can obey commands as if they really understand.

But after some months, the dogs went back to their rowdy behavior. Sooner than expected, they do not follow commands anymore. The vet said that our dogs are spoiled so the training has been wasted. Okay, it is our fault.