It isnt a figure of 8 Lead its hard wired only option is just to use a standard EU adapter or cut the plug off and void the warrenty which I wouldnt recommend, obviously a stock misunderstanding at OCUK or something and the only way Logitech could sort it would be to send you a new sub so the EU adaptor is probably the easiest(Only about a pound from anywhere really).
Well for some reason the ones coming from OCUK at the min are EU plugged and hard wired.
Bit odd tbh.