THIS IS WHAT YOU DO:
1) Phone them up press the button that says you are thinking of leaving,
2) They will ask you why just say you have found it cheaper elsewere you do not have to say were. Don't listen to any of their bullcrap about speeds fibre all that just say you have made you mind up and that's it.
3) They will put you through to retention's and try to persuade you to stay and there and then they will try to find you a new deal but:-
"REMEMBER" at this point you have not officially left so the deal they will offer you will be utter garbage crap deal like £10 of or something
so make sure you;
****DO NOT UNDER ANY CIRCUMSTANCES ACCEPT IT - - - DO NOT ACCEPT***
I cannot reiterate this point any more clearer DO NOT ACCEPT THEIR FIRST OFFER just keep saying I am leaving. They are good at trying to keep you just say nope my minds made up I am leaving. They will read out all the bits about 30 days notice and sending the stuff back in the box they send out.
4) This department, Stage No1 of retention's do not have the best deals because you have not officially left. You will only get the huge best discounts when you have left and they call you back in a day or two. This is because, once you have hung up you are officially leaving and your name will go on the leavers retention's list and to be called back in a day or two with the very best offers because ? you are leaving.
5) In a day or so they will call you and that's when you drive the best deal. Barter like your at a Turkish market don't be scared to be hard faced. Even this person first deal will be sh*t. Keep mentioning new customer deals and you want what they get.
6) If you upgrade any equipment make sure they waiver the £100 installation fee and watch out for the £35 contracts fee add-on get them to scrap that., that one takes some doing. If they don't mention it make sure you don't mention it because, if he doesn't tell you about the £35 charge then when you get your first online bill and it's listed and you haven't been informed ring them explain he never mentioned it and they will scrap that.
my bill was £60 odd a month and after doing the above I got it to the price of a new customer nearly half of what I should be paying.
I'm sorry for going on about the leaving bit but that is the key to it all. You must officially leave and hang up then get the call back to get the very best deal. If you get put through to retention's first time round the deal will be nothing like the deal you will get when they call you back so be brave and hang tight they will 1 million percent call you back.
New contracts are 18 months so this is why you negotiate hard 18 months is a long time.
Good luck