I lost you, in the title you talked of a WAN port? 
It is entirely possible that you have changes in the configuration that reverse the default logic of Mikrotik (winbox access only allowed from LAN side)
Anyway, if you can somehow connect with winbox from one of the ethernet ports or via WI-FI, follow these instructions:
http://forum.mikrotik.com/t/forum-rules/173010/1
and post your configuration.