In the end we pushed them back and repaired the walls. The battle went on for over an hour and EP won against overwhelming odds. DC use lots and lots of resources only to fail. Now the moral of this story is:
1. If you're going to tear down 2 walls do them on opposite sides of the fort to distract those inside.
2. Never attack the main door.
3. Never ever, ever, ever use a ram especially on the main door
4. Anyone ever suggest using a ram I'll take a ram and well you don't want to know what I'll do with it.
Also thanks Jammer for your siege bubbles and your help.