@screamer I got a call back yesterday at 5pm, double checked I was past 10 weeks and with less than 2 weeks to travel, then put me on hold to pass me to the upgrade team, on hold for 51 mins then the call just cut off.
I then called 0300 330 0901 again which only got me put me back on the call back list. That call was returned at 2pm today. This call started the urgent upgrade request and instructed me to email escalatedservice@hmpo.gov.uk with relevant details and flight booking evidence attached.