Tom, I once purchased a JCB circular saw from Argos, as it happens it's still working but if I need any parts or service I'm stuck. Before I left U.K. I tried to check with the JCB Customer Service number but after endless attempts I couldn't get through. My e-mails went unanswered, as did a FAX I sent them :x
Which JCB company did you eMail/Fax Losos? The phone listed JCB Customer Service in the UK is for their Diggers etc, they have nothing to do with the JCB branded saws and Routers etc. Was there a service card supplied with your Saw? Amazon are also selling JCB power tools - I would guess that either they or Argos should be able to point you to the service agent
I think JCB must have licenced their brand - it is also on shoes, clothing and gardening gear!