Please Help! Im at my witts end!!

Question

Im praying someone here can give me some advice, if i could find someone from BT to go and see i would. I have never recieved such terrible service from any company. 
Ok, my problem.. Ill give you the full story. Was a very happy customer with ZEN internet, and just over a year ago i left them and moved to sky on a package deal, was happy with that but funds got tight and we let the sky package go. Internet is very important to our house so i decided to go with BT.
I called BT before putting the order through online, The person on the phone was brilliant, they understood all the hard work Zen had done with my line, having interleaving turned off and various other things, i wanted to confirm they could maintain this level of performance. I was assured it would be the same or even better!
We migrated on 24/03/10 and the problems started imediately. The line was almost unusable for 10 days, BT assured me this was normal and that my line would settle at its optimum level. 10 days after i was on the phone complaining, my speeds downloading from servers i have used for years were slower, my pings much higher (interleaving on!)
after many calls to Tech support i snapped, and using the complaints form i wrote a pretty strong email where i was contacted 5 days later by a very nice chap who really seamed to care about my fault. (date at this point was april 10th)
The conclusion of this contact was that my download speeds were increased 3909Kbps to 5145Kbps. Looked good, Bt still not providing me with the same line speed i had with zen, but we are only 400Kbps off.
Well, thats only part of the story. Despite BTs speedtester reporting this increase in speed, i was suffering incredible lag, kicks from servers, and even problems streaming low quality video from youtube.
I had to go away for a week with work, but when i got back the problems were as they were, so another phone call to BT tech support, Who asked me to try different machines, different filters, plugging in to the test socket (im so tired of doing this now, it must be 20 times)
I have been promised call backs over and over again, despite me telling them the hours i work, they still call when im out, if at all!
i complained again 5 days ago, no response at all this time!
this is what i have... from speedtester
 Download speedachieved during the test was - 5145 Kbps
 For your connection, the acceptable range of speedsis 2000-7150 Kbps.
 Additional Information:
 Your DSL Connection Rate :5728 Kbps(DOWN-STREAM), 448 Kbps(UP-STREAM)
 IP Profile for your line is - 5053 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 12.99:28.63:58.38 (SBE:NBEBE)
These figures represent the ratio while sententiously passing Sub BE, Normal BE and Priority BE marked traffic.
The results of this test will vary depending on the way your ISP has decided to use these traffic classes.
But this is what i get from my hub
ADSL Line Status
Connection Information
Line state: Connected
Connection time: 0 days, 00:25:07
Downstream: 5.594 Mbps
Upstream: 448 Kbps
ADSL Settings
VPI/VCI: 0/38
Type: PPPoA
Modulation: G.992.1 Annex A
Latency type: Interleaved
Noise margin (Down/Up): 8.3 dB / 23.0 dB
Line attenuation (Down/Up): 44.9 dB / 28.0 dB
Output power (Down/Up): 20.1 dBm / 12.6 dBm
FEC Events (Down/Up): 18099 / 1
CRC Events (Down/Up): 17 / 0
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
HEC Events (Down/Up): 76 / 1
Error Seconds (Local/Remote): 9 / 2
ADSL Line Status
Connection Information
Line state: ConnectedConnection time: 0 days, 00:50:07Downstream: 5.594 MbpsUpstream: 448 Kbps ADSL Settings
VPI/VCI: 0/38Type: PPPoAModulation: G.992.1 Annex ALatency type: InterleavedNoise margin (Down/Up): 8.3 dB / 23.0 dBLine attenuation (Down/Up): 44.9 dB / 28.0 dBOutput power (Down/Up): 20.1 dBm / 12.6 dBmFEC Events (Down/Up): 18099 / 1CRC Events (Down/Up): 17 / 0Loss of Framing (Local/Remote): 0 / 0Loss of Signal (Local/Remote): 0 / 0Loss of Power (Local/Remote): 0 / 0HEC Events (Down/Up): 76 / 1Error Seconds (Local/Remote): 9 / 2
Its rubbish, i have had enough, is there anyway i can get out of this stupid contract with BT on the basis they are not providing the service they promised? dont get me wrong i would prefer it was fixed by them but i really cant face being asked to change the filters again, or plug into the test socket... i cant even get my problem listened too by someone above the most basic level of tech support!
any help and advice would be appreciated!

Answer 1

Thing is i know the profile says its the same as zen, what im saying is actual performance at this end is nothing like i had before
Speed test says one thing, actual speeds are different. Yes i can download like i have a 5Mbps line for 10 seconds, then i time out
Update
ADSL Line Status
Connection Information
Line state: Connected
Connection time: 0 days, 02:25:03
Downstream: 5.594 Mbps
Upstream: 448 Kbps
ADSL Settings
VPI/VCI: 0/38
Type: PPPoA
Modulation: G.992.1 Annex A
Latency type: Interleaved
Noise margin (Down/Up): 8.4 dB / 23.0 dB
Line attenuation (Down/Up): 44.9 dB / 28.0 dB
Output power (Down/Up): 20.1 dBm / 12.6 dBm
FEC Events (Down/Up): 151333 / 1
CRC Events (Down/Up): 349 / 1
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
HEC Events (Down/Up): 1202 / 3
Error Seconds (Local/Remote): 156 / 4