Sorry to hear of your horror with this service too!!
I did sit in a queue for 2hours earlier, although I still not much further forward. I’m not sure if this will help but I was given an email for Durham upgrades, if you want to try….
DurhamUpgradeTeam@hmpo.gov.uk
Good luck and hope you get sorted soon. 🤞🏼
I’ve accepted the fact I’m not flying this Friday. Deeply disappointed 😥