Does anyone know how to complain to Openreach?

We moved into new place 4 weeks ago and have not had broadband since. There was a BT broadband connection with previous occupiers so I assumed that our BT router wouldn't be an issue.

BT tell me that broadband is connected but it isn't.

Twice BT have arranged for an engineer to come out and twice they have failed to turn up.

Yesterday I happened across an Openreach engineer visiting another apartment and he kindly checked my router and wiring and confirmed it was OK. He did happen to mention that there was an external fault. So, if Openreach are aware of issue why don't they fix it?

I have complained through BT executive team and,so far, received £200 in compensation but no internet.

There seems to be no way to complain to, or about, Openreach. Their email address return mails and they are not signed up to Ofcom.

Any ideas how to reach them?