Can not download / integrate the addonBrowser Info Environment
Can you give me a bit more info. What do you see on the "Extend" page, errors or the Add-On not showing up or... There are literally hundreds of people using this and have never had this issue pop up. This looks to me not a problem with the product (Block Designer) in this scenario.
Just post a few screenshots of what you see (or don't see) and if other bought products work or not (maybe not correctly linked account).
Do have to point you to the refund policy though:
Since it all works okay and refunds are very costly to concrete (owners of the platform), I can not grant you the refund. If you really do want a refund for the working product, you'd have to contact the site administrators for that!
If you have any more questions, let me know.