I had something similar when I moved away from IO and then went back a few months later. It eventually worked, you just have to ignore the error message as I have an Ohme charger which controlled the charging anyway.
I don’t think a p90D 2016 is worth £30k privately, maybe £25k tops. All EVs have come down in value, even the Ioniq 5 with the 77kWh battery can be had for around 27-30k and they were 55k 18 months ago.
Similar to above 71 plate SR+ went up from £350 to £650 with renewal from Direct Line.
Price comparison websites wanted 700-900 and that’s the basic cover; I noticed many of them don’t offer driving abroad anymore to keep the price “low”.
I wouldn’t argue with £176 if they are replacing it with a new one. Knowing my luck, they’d call the manager for a second opinion and he/she would say that it wasn’t a valid warranty claim and present a bill of £1000+