I don't know any shop that would swap a bredli for a diamond. Didn't you only get your bredli in October? If so you have two more months of living with it before you can dispose of it.
From all your previous posts it sound like the bredli is stressed. I would probably have multiple hides in the enclosure and either have the enclosure in a quiet room or cover the front for a few days. I would not handle or stress it out for at least a week, only doing the bare minimum, such as changing the water every second day and spot cleaning when it is asleep in its hide. Then I would give it a feed then leave it alone for another week.
After that, then I would begin handling it for a couple of minutes each day or so and slowly increase the time.
All these steps are meant for animals you have just purchased but since it seems like you haven't left it alone since you brought it home, they seem appropriate to let it settle in and feel safe. If you follow these step and it still is defensive then it seem you may have yourself a nice display animal. For me personally I get a lot more enjoyment out of watching and looking after my animals than handling them.
