...can I tell them to shove it? If I'm not getting a sufficient level of service (or they intentionally degrade it), surely I'd be within my contractual rights to tell BT where to get off?

Depends on what you get throttled on I supposed, it's torrents, then I reckon they'll tell you to shove your complaint, but if they just do it, I reckon you can complain.

I've noticed they've started throttling my service at "peak" times...anything from 5pm to 2am, which means that most of the day its simply unusable - sometimes even ordinary web browsing is a chore. The service seems to be getting worse, and pretty soon I'm going to start complaining.

Same here. Seems that they are deliberately throttling youtube still. It's odd. Zero punctuation loads and buffers really quickly, but a similar length & quality youtube clip has to be paused and left for 5 minutes to buffer. Normal HTTP file downloads are reasonably quick though.

They're obliged to give you a mac code fairly quickly.

Yeah, I would get onto the phone to them, see if they've done anything, doubt you'll get anywhere though.

They have been accused of throttling iplayer streams. clicky

If they throttle torrents or usenet, you can guarantee it's in the small print of the FUP and you'll be lucky to get any change out of them, unless you can prove you don't use them much.

I'm on the "unlimited" F2S package, which I paid extra for because I like to download a fair bit.

http://www.freedom2surf.net/adsl/homeuser.php

Since CPH took over, they've started throttling torrents from 5pm to after midnight. It goes down to less than 1K at 5pm, and now I should be going to sleep it's just barely crawled back up to 30K.

There is no FUP that I can find on the website for the package I paid for, and it's annoying me greatly. I still have a year to run on the contract, and I've been thinking about complaining. Notice however, that the "Premium" product has a garanteed speed of 50Kbps on a 16Mbps line. WTF? You have to pay yet more to get just 0.3% of the headline speed? That works out as a contention of 300:1 on their top product!!

Unfortunately, my exchange is not scheduled for LLU and there's not likely to be cable any time soon. It's almost like pre-broadband, and partly explains why I'm often awake at 3am on a school night.

I've kind of accepted that they throttle torrents (what ISP doesn't these days?) but when ordinary browsing & stuff like iPlayer and Youtube don't stream at all, then I start getting majorly peeved. I'm on Option 2.