If treats aren't doing the trick and your pup's still not coming when called, don't scold them! This certainly won't motivate them to come any quicker.
"If your dog is not coming when called, quietly walk over to the dog and clip the leash on yourself," Tori explained. "Don't punish or scold them! Talk to your dog in a nice voice, or even praise them. That way, it'll be a lot easier to leash your dog and leave the dog park, now and in the future, than if you were to scold them for coming too late."