want to cancle BT

sugarplum10

I have had problems with BT for the last 3 months. I moved into my new house 3 months ago and set up BT broadband option1 and evening/weekend calls.
I explained on the phone that myself and hubby have laptops as i need to do uni work and he needs to access his work account and that we stream our TV through the internet as we dont have a TV.
This is the package that they sold to us, they tested our line and said that we could have up to 16mb from our internet but our line was testing at 15 mb.
I agreed to this package and set it up.
We do have a connection but sometimes its so slow that we cant even access ebay or internet banking as the security settings time out before we can get in_ it is that slow.
we have phoned on numerous occasions and run the line tests through the speedchecker page and we get anything from 7-14 MB depending on the time of day. sometimes we can use it fine and other times it takes an age to connect.
At uni my lappy connects straight to their wireless and runs perfectly fine its only at home we have these issues and before we moved to this house we had BB with plus net that was also brilliant (but in our old house).
WE made the decision to go with BT based on the claim that we would have such a great service.
everytime i have called them i have noted the date, time and person that i am speaking to, on occasion they have admitted that there is a fault on the line that they can see from their end and other times they have said there is nothing wrong. we get told a different rewason for the fault each different person that we speak to and frankly we have had enough.
on top of this they have been sending our bills to our next door neighbours. we have complained about this several time but still they are being sent to the wrong house!
I want to cancle it now and today after having yet another bill sent next door and another week of calls to them i asked to cancle, i was on hold for 50 mins to bve transfered to the wrong person twice and finally customer care who said it will be a £182 charge unless i prove i have had bad service.
how can i prove this in retrospect???
please help, as we have seriously had enough now.
also during the olympics my hubby tried to watch the track and field so downloaded it to his computer, it timed out and said an error that we had 'insufficient bandwith to support the download' over 30 times and he had to download it again, we have now been charged for going over our usage- this is total !!!!!!!!! it seems it has counted the download completely each time even though we only really downloaded it once. Im just so upset by their inability to provide our correct service and their bad customer service when we call them about it.
whay can we do to resolve this???:mad::mad::mad:
BT need not reply as i think ive spoken to you guys enough over the last 3 months and gotten no where.