I suddenly started to get promotional email from Tesla to my work account, this indicated that someone had registered my email address for a tesla account (I had one previously on my home email address - but I am going to sort out consolidating them once I get past delivery!), so i went to the tesla site, put my work email address in and hit reset paissword link. It worked, I got an email and could now log into the tesla account pages as me (work me). No information in there is any use so why am I telling you this?
This account creation seems to indicate that an order has been placed
Tesla might just be willing to talk to you based on you providing your email address and possibly, if you tell them your story, be able to give you the RN? I don’t know.
I know when I’ve phoned Tesla in the past when I couldn’t find the bit of paper I wrote the RN down on, the agent asked for my Tesla account email address, so maybe you could get it that way - perhaps it depends who you get!
In my case I didn’t have to as I’d received an order number from our company car scheme provider and so chased them directly for the RN, which they gave quite easily (This was ALD)