You've proven that the broadband from your Xbox is working fine, so there's nothing more BT can do to assist with this unless Disney provide any specific requirements that they may have. Contacting Disney is the best route to identifying the fault - it may be something they already know about. If it's something common to BT users then we can also then brief our helpdesks on it and provide a help article for it.
As for port forwarding - if that is a genuine requirement then I'd be very surprised. Microsoft should have set it up with UPnP if that were the case.
