HiSounds like a game of pot luck!
Have you asked them how they came to that conclusion and specifically why they refused Mpv?
Perhaps it would only be a minor amendment to your setup to satisfy them?
Too be honest my intensions were to make them explain their reasons as I was going collect as evidence as I could to prove their hit and miss approach to requests of this nature.
As I said I have some one who is buying my van so I needed to get my v5 back quickly, but I will try with my next van and will take it as far as I can.
You may be one of the lucky ones and they may let it slip through