How to make a hamster happy

[WhoNeedsaLammyInTheWorld]

Relative bought a hamster from pet shop. Biggest cage they could get. It was a bit jumpy from the start and prone to biting
Relative has turned put to be allergic so I am looking after it and will probably keep it. I feel bad for it. It doesn't seem happy (I think it is pretty cruel to keep them) the cage is far bigger than the recommended size. It did have tunnels but relative read they could be dangerous and removed them
I would pay for an even bigger cage if it improved its life. It doesn't seem to like company

The skyline barney is still available
Is that big enough
I do like the wooden one with different levels but there doesn't seem to be much depth to burrow

We have 1 Syrian, 2 Dwarf Hamsters and 1 Dwarf Robo Hamster. I have just purchased 3 of these . We have wheels and tunnels and little houses for them and different toys and wood bits to chew on. This gives them the floor space they need and will have sufficient bedding in for burrowing.

Meant to tell you what it is called!! Here are some more details we adore our Hamsters and they all have time out to run around a pen. We just have to double watch the Robo dwarf as he is like Usain Bolt on Speed!!