You are correct, that is what he said on the phone. However when I arrived at the site, both the guy from the phone call and his service manager was there. I asked specifically if update 27T7 had been installed, and they said actually no, there were no updates installed, because there are no recalls or updates due on the vehicle. He said that he meant that various tweaks in the settings were made to improve the charging for the HV battery.
I get the strong feeling that they don't know what they are talking about. The VW dealer who I bought the vehicle form is around 80 miles away, whilst the VW dealership that I was taken to by the VW Emergency guy is my local one, that doesn't sell Cali's, it only sells vans. Whilst that shouldn't maybe make a difference in theory, I think it might do in practice.
I will leave the vehicle on my drive in the coming days. if the battery drops significantly, I am going to take it back to the selling dealer and leave it with them.
I checked on the screen in the rear compartment when I got home, the 12V battery was at 70% charge and showing 3 AMP's being drawn whilst parked up.