Hi Speedtouch,
Your only real option here is to ask / insist for a MAC (migration authority code)
Once you have this you can migrate elsewhere.
My advice to you (and everyone else) is NOT to tie your broadband in with other products /deals.
STICK with BT for you phone line rental, and have a cheaper call option package by all means with another provider (such as utility warehouse) BUT keep with another independant provider for broadband. Using BT for broadband is a clear advantage since BT "owns" the whole network (i.e.the "problem) - but it's not essential for this reason alone to go with BT
Once you are in this situation - ALL telephony issues relating to your phone line - upto your master socket (assuming that any internal phone wiring to extension sockets has NOT been installed by BT) is the clear responsibiltiy of BT, and ... any Broadband issues are the responsibilty , initially with your internet service provider. - I say "intially" becuase some of the broadband issues are still the responsibilty of BT - such as your actual phone line, which carries the broadband signal from the exchange, and in most cases, the terminating equipment in the exchange (i.e not LLU)
As you are at the moment, there are several things you can do to "help" yourself.
Have you looked at measuring the line loss and noise margin figures ? (most good ADSL modems will allow you to "see " these figures - these relate to the quality of the basic broadband signal reaching " your end" - and also a measure of how much "interference" is being superimposed on your broadband signal.
If theses figures are poor - then this means that your modem is "struggling" to hear the broadband signal - and this will mean "disconnections" every now and again - and IF this is due to poor wiring etc "your end" - then changing supplier WONT make any difference !!
Also - if you suspect poor connectspeeds - try logging onto the BT test realm (this means changing temporarily the user name in your modem / modemrouter and perfoming a speed test ......
have a look at:
http://www.more-solutions.co.uk/support/bt-test-user.html
The thing is here is that you really need to KNOW where the problems lie before "jumping ship" - because as I've said - it may not be all the fault of TT !!
But - having said that - as I've said before - you do get what you pay for - and some of the smaller operators like us like to think we give better customer service and advice ( like here !)
Regards
Eric - ISP