I can't comment on your particular case, but it sounds odd that they didn't help out. Certainly not my experience with their support so far (and I've been with Linode for probably 4 or 5 years now and used their support on many occasions)

However, it's so easy to fire-up another linode, shut down the host, move the disk image to the new linode, assign it and turn it on. You get a new IP, and can get rid of the old one. And all this via their web interface and with no need for support...