I bought my two females four weeks ago when they were about two months old. They were terrified, they had obviously never been in contact with humans except for feeding and cage cleaning. They had no idea what cucumbers or carrots were, and they panicked whenever I made a movement or a sound.
Four weeks later, they're still shy but happily exploring everything I offer them. I have not taken away their houses (though I considered it) cause I thought it would be very cruel since they were already so scared. I preferred to wait until they got curious, and curious they got! Especially when they smell cucumber. They take it from my hand now and eat it outside their houses which is a great reward for my patience.
I haven't held them once since I bought them. It will take a lot of time till they trust me enough so I can pet them. But I think they have the right to take their own time. When they are ready, they'll come - even if it takes another four or eight or more weeks. At least then I'll know they decided to trust me instead of being forced to.