Well - you could try for a refund maybe. If not, it would be good to keep as a playcage for when you're doing cage cleans. I use a pet carrier for that at the moment. I agree about the Barney - and it's good value - and less to paint with plastikote (pet-safe waterproofing paint). Although it wouldn't matter if you didn't paint them - houses and shelves can be replaced - but it can save a bit of money in the long run. The Plastikote costs about £4.50 a pot and one pot should easily do two coats on the inside of the house and on the top of the shelf
I would suggest trying to upgrade your hammy as soon as you possibly can or he could start developing stress behaviours like bar chewing or just getting lethargic.
If money is an issue right now, you could go for the Alaska and make a shoe box house
Cut a hole in a shoe box for a door and cut the floor out and put the house on the substrate. Makes a nice house that's dark inside and has a roof for a shelf and a lift off top so you can spot clean inside it
Cheap to replace as well.