I wouldn't actually say the support staff "knows" linux. Times I've had to call, (which was only because I IpTabled myself out of the router -- idiot) the service people were friendly and sympathetic, but with NO experience of *nix. The fellows I talked to tried their best, and actually took notes from what I said I was trying out (ifconfig, route and friends), but actually told me that their boss was giving them dirty looks for trying to "support" one of those Linux people. Their manual, interestingly enough has sections on UNIX installations, which basically back out of it all by saying that typical *nix users are smarter about all this stuff, and should make it all come out fine by setting up their own flavor of DHCP.
Most IT staff at call centres are hired/trained to use Windows and thats what they guarantee to support. Sometimes they fear people going off and supporting Linux, although not having that guaranteed gives them a good get out clause, "sorry we don't officially support this".
If you know of genuinely *nix-savvy tech support folks there, could you mention names? I'd ask for them by name at need, and send kudos-type emails to their managers commending them for their Linux expertise.
Might get them into trouble with their bosses for suporting an unsupported product. But then every call centre has its own rules :). Was always nice to get an e-mail from a customer saying you did a good job (especially if they hired someone to fix it for big bucks and they failed to do so). Matt
Cheers.
Michael