Off the top of my head, either some entirely internal process designed to kick the issue into the long grass, or some entirely made up bollox designed to make you lose the will to live.
The bottom line is that they have negligently injured you (damaged your property) and you are entitled under the law of tort to be made whole (be appropriately compensated).
If there is some alternative process, other than suing in the county court, that is beneficial to you (e.g. if there is an Ombudsman that will hand them their arses on your behalf - which I would assume there isn't), then it might help them to tick the appropriate boxes to that process.
Unless Openretch (no longer called BT Openretch, but still wholly owned by BT) have told you that Keoghs is their address for service, Openretch @ <Openretch's registered address> is the correct address for service. However, it may be prudent to follow up on your original complaint to Openretch asking them to confirm their address for service (effectively a nudge before letter before claim).
There is an expectation that both parties will behave reasonably, which arguably includes not going straight into threats of litigation - although the letter before action (which is very much a threat of litigation) is the only mandated step. For the matter to be kicked down the corridor to the wife's cousin's hairdresser's catwalker, who then takes the thick end of a month to respond to the effect that they might get around to looking at it within 3 months, but only if they feel like it, suggests that if you try to be any more reasonable, they'll charge you extra for the vaseline.
so a little update.
an email to Openreach CEO got a response same day from 2 people who were profusely apologetic and assured me they will stick a rod up err... investigate Keoghs position. que another 4 weeks of precisely FA. So today another few emails to the top brass at openreach secured another response from the same guy saying he would again stick a r ... investigate the position but could not get involved in the investigation or direct Keoghs to do anything despite being the principal to their agent Keoghs.
Ta da, an email from team leader at Keoghs explaining that the "90-day protocol" is in fact Civil Procedure rules ...
"
Civil Procedural Rules allow the Defendant 90 days from receipt of the statement of claim (Claim Form) to investigate and reach a decision on liability. For legal liability to attach, the Defendant must accept or the Claimant (yourself) must prove negligence by the Defendant. Liability decision will be notified to the Claimant (yourself) as soon as possible, within the 90 day period.or in my language.. "we've got 90 days so we are taking all of them to investigate liability and are ignoring the cctv footage you supplied of them actually carrying out the damage"
this is the first ive heard of Keoghs being Openreach's insurer as from what I could see they are a Legal firm.