In reply to:
and said its fine but did say that my voyager 210 could be the problem because its overheating.
I hate to say it but it sounds like you've been fobbed off by the engineer. Routers / Modems will get warm or even hot to the touch but won't drop a disconnection for this reason. If anything when computer electronics get too hot they'll usually freeze or just 'let go' (in other words stop working completely).
If you really want to speak to someone in the UK (and trust me you do!

) then an option is to call up 'broadband sales' I think via 150 and get them to put you through to the right department by telling them that an engineer had put one on order for you. I believe at one point "sales" used to be a UK call centre and still is (unless that has gone to bangalore too).
Might actually be quicker to purchase a new modem / router yourself from somewhere like
http://www.broadbandbuyer.co.uk or even a trip into (horror) PC World.