Complaint: unhappy with level of service.

Question

As with what is apparently a rather large number of people, I am extremely dissatisfied with the service I have been receiving from BT.
My broadband speed has never been even close to that which I am paying for, or even that which I am capable of getting around here.  Recently the speeds have started to fluctuate between a decent speed asnd whatever comes right before zero.  My Xbox Live connection constantly drops due to it hitting 0, and yes, I do have the port forwarding configured to allow the service to run.
I have contacted the help desk, who are about as trained and useful as my three year old nephew, or even his dog (case in point: whilst in an online chat, I was told to reset my router and that it 'would not drop the line')  I am repeatedly told to do the same things: reset my router, try the master phone socket, run speedtests, the works.  It even reached the point where I was phoning the helpdesk so oftne that I would pre-empt things by doing this beforehand.  I was still told to run these banal and pointless tests because the helpdesk staff were 'unable to proceed unless I did'.  They're following a **bleep** script.  And not a very useful one at that.
On no less than 3 occasions in the past few weeks I have been promised callbacks from the helpdesk staff, I give them my mobile number EVERY TIME, despite the fact that it should still be on file, and a time to call me back.  I am now still waiting on these 3 call backs, each one from a higher level of helpdesk staff, I'm fed up with having to wait for these calls which never happen.
None of my problems are am issue with my computer or operating system, as I am experiencing the same fluctuating speeds on my tablet (Android 3.something) my phone (Android 4.something) two laptops (one Vista, one XP) and my 360 (running whatever the heck cut down version of Windows it is) and it occurs through both cable and wireless.  The only way I get anything close to a reliable speed is by using a very short cable directly connected to my router.  Anything over 6 foot and things slow down again.  I'm typing this sat against my front door.
No-one seems to even care that I have a problem, as even complaining direct via email (which apparently will illicit a response within 3 days) has yet to get me anywhere (Still waiting on a response from 5 days ago).  And yet, I'm still expected to pay my bill every month.  On ore than one occasion I have been promised a reduction in myh bill or s refund of some discription for the inconvenience, but I am yet to see any of this.
So it's time to complain about it in a public forum, where other people can weigh in on the way in which I have been treated.
I am in the middle of penning a little letter to the various higher powers, which will include that nice Mrs Robinson off that Watchdog show, and several national papers, unless someone can do something to rectify this situation swiftly.

Answer 1

Thanks for the speedy reply.  I know that the forum mods are the only employees that read it, I just needed to vent my frustrations to people that would actually listen, because no-one else at BT is actually going to do it.
Do I need to login to my router to get my ADSL stats?  I only ask because for some bizarre reason, my router will only accept my password from the XP laptop, not the WIndows 7 (I said Vista before, I meant 7) one or the Android devices.  I'm also on my third different router as I thought the issue may have been my Hub2.  I borrowed an old Netgear from a friend (and I mean old, no n-band wireless) and that seemed to solve things, but the absence of wireless was an issue due to it not having an aerial, so I acquired a hub3, which just brought back the problems.
We've only got the one active socket, and the last time an engineer came round he fitted what I presume is the BT accelerator, which I understand is essentially a permanant connection to the test socket.  In any case, I have since had the front off of the box to try the test socket (I think it's the test socket).  I do use powerlink adaptors to expand my LAN upstairs (4 story house, possibly lead lined walls, we basically live in a faradya cage, so the effective wireless range is kind of limited through no fault of the router) but this has never been a problem until the recent fluctuations.
Not tried the quiet line test, but we don't have a corded phone, so I'm not sure what result I'll get.  Would that explain a fluctauting speed though?
Bt speedtester always seems to hang on me.  I've only ever had a successful read out of it once.  Seems that BT can't even get that right.