BT / Over charging

This is an ongoing complaint about BTthat has not been dealt with.
I changed my mobile package to 600 free minutes and 400 free texts to start in September 2008. This was arranged over the phone. I was sold e phones.
I e mailed and phoned to report this on several occasions but was not dealt with properly and still my new package was not applied and I was charged for minutes that I had used because I was assured that I was on the 600 free minute package, in addition I was charged GPRS although I was told this was free.
I e mailed to the complaints on the following occasions;
13/11/2208 - ref. [protected]
18/11/2008 no reference given just notification that mt compaint was passed to a complaints manager.
I wrote to the company after obtaining the address from a sales advisor detailing all of the problems I was encountering.
I again e mailed on the following ocasions;
07/12/2008 ref [protected]
11/12/2008 no reference given, but a note from Sajiad Ahmed saying he hadn't received my previous e mail.
I am given the number over the pnone of a Louise Maher but after trying over 25 times the line is constantly engaged.
12/12/2008 reference [protected]
Still I have not had a response.
I cancelled last months direct debit as I have been grossly over charged and cannot get an answer to any of my e mails.
My outgoing calls have been suspended.
today Ihave tried to ring Louise Maher 7 times but still no answer.
I have tried to contact OTELO and they require a deadlock lettet to be able to take on my complaint.
I need someone to respond as a matter of urgency.