As we have described in great detail to you, in many previous communications, Co-Op vault payments made via our service are non-refundable, as are credit deposits, other than in extreme circumstances. The credit will of course never expire in your account, but can not be withdrawn. Not only is this covered in our Terms of Service, but is one of the core design principles behind co-op vault; the money there is guaranteed to be always used for server purchases at NodeCraft.com, and never withdrawn for other purposes. This concept is what makes it such a desirable system for many users, as they feel safe that their money is contributing directly to the server hosted at NodeCraft.com.
If you would like to discuss this further, we'd be happy to in the form of a ticket, or any other support method that we offer.