If a fault has been detected and Openreach have been tasked to investigate, then actually speaking to BT doesn’t achieve anything , unless you suspect your account has been ceased , if you suspect an error by Openreach has disconnected your line , the fault report already raised is necessary to sort it out , there is no insight BT could offer and no way to expedite the repair because of it .
Faults happen , Openreach get something like 30p a day ‘rental’ , so fixing within 2-3 working days ( the day of the report doesn’t count ) is by any measure a pretty good deal , it could get fixed quicker , the 30th will be when compensation starts .