Location: B'ham (nr the airport)
Joined: Dec 2008
I think your pup is confused abotu the function of the crate. Does he sleep in there happily during the night? If so, then he knows it's a place to sleep. And not many pups wuld refuse to go in if food or treats are on offer.
When you're at home with him, does he get sleepy or restful after a walk, playing, training of any sort? If so, make sure he's worn out and then offer him a reward for going into his crate. Don't lock him in as it's not necessary when you're in the hosue with him. But he will learn in time that it's a safe place where he can be on his own. If he thinks he's going to be shut in there for any length of tiome (other than to sleep overnight) he may be reluctant to go in there at all.
As you've only just gone out to work and left him inthe confined area weith the option of going in his crate, I'd persevere and give him time to get used to it. Clean up any mess, regardlews of whether it's in his crate or not, withuot reprimanding him.
Replace his blanket or bed with a clean one or new one (one which doesn't have the scent of his messing onit) and start over. Again leave the pee pads on the floor by the door should he need to use them. Put his crate as far away from these as is physically possible within the confined area. Thsi way there is no mistaking where he sleeps/rests and where he pees when you're not there.
Also, instead of his usual kibble inside the kong, try a few pieces of cheese, or sausage. These will be far more attractive to him and is a far higher value reward. SO he'll learn in quite a short space of time that he must go into his crate to get the best rewards.
He's only young yet. Don't give up on the crate training yet. If you give up on it now after only 3 weeks, what happens in 3 months, 6 months, 12 months etc down the line when you're training obedience and he doesn't grasp it straight away? Will you give up on him then too?
Sometimes it takes dogs longer to learn what we're trying to teach them that we would like. Just keep trying. You've not mentioned any real problems with his behaviour etc so I don't think you have anything to worry about.