Sounds like the script worked to me. This is a case of customer error and a bill would have ensued if a more 'clueful' provider's support staff booked an engineer to visit and unplug the errant customer premises equipment.
Er, no you don't need an engineer, but the first helpdesk call should have said "oh, you have a white openreach modem? but you are on BT Broadband that doesn't need one" - and everything would have been good. As it is, the OP is not impressed by BT's helpdesk, and most of the people reading this thread are not impressed. Brand is not as good as it could be.
James BT Infinity 2
19/09/2012 - Sold 42/6 - Getting 46/10 - Sync 54 / 11 Mbps @ 470m approx
14 years of broadband (ntl: cable to BT FTTC) - Router: Asus RT-N66U - Modem: Huawei HG612 speedtest