Our terms of service state that "The 30-day money-back guarantee does NOT apply to domain name registration or other domain name services".
Domains are purchased on your behalf and set up for you. This involves time and expense to us and we have no way of returning a domain once it is bought for you from our domain registration partner.
Your domain remains your property for the period for which you registered it, whether you decide to make use of our free sitebuilding and hosting or not.