Fraudulent sales pitch

Have we got good enough protection against unscrupulous online phone sales?

The phone call came at 8:40 this morning. 'Hello,' I was told, 'I'm calling from your telephone provider, offering reduced rates.' She started waffling on about reducing the line rental and even owing us some money. I interrupted. 'Who is my provider?' Long pause. 'Sorry?' I might have started sounding a bit aggressive at this point: 'You must know who you are!' 'This is BT. Do you have broadband?' Whoa, now. I went into attack mode: 'If you were BT, you'd know.' The response is a long pause. 'You must know if I've got broadband. You tell me.' Another pause. 'Sorry, I said I'm from EE...' I told her this was a fraudulent call and hung up.

Now I have no idea if she was really from EE or if this was an out-and-out scam - she certainly wasn't from the UK - but either way, this was a clear attempt to fraudulently persuade me into agreeing to change to a different contract, or just to get bank details to rip me off, by lying about who was calling.

The trouble is, I really don't know who I can sensibly complain to - even if it was EE, and I have evidence of that, I'm sure it would be denied. And, of course, it was an international call with no caller ID, so no come back and no TPS protection.  I'm seriously considering just blocking all international calls from now on.