I've just sent an e-mail to TM with a screenshot of my speed test results and a long complaint on why I'm sure they mis-capped me and what trouble has it brought to me:
http://img543.imageshack.us/img543/9053/speedtestresults.jpg

My subsciption is 1Mbps and I've never got speeds over 600kbps which is rather annoying.

Do you think they will care about complaint e-mails?