I dont have any extensions just my master socket
I called to cancel my bt account today as bt keep warning me of possible charges,
I got through to a guy in india he passed me to his supervisor
And I said I was that fed up with BTs black mail I wanted to cancel my BT account he sorted out a free visit from an engineer this saturday,
He said as long as my phone was not causing the noise,
And I did not have any faulty extensions on my line,
Then the call out would be free
and hopefully the engineer will now replace the offending cable or box
fingers crossed.