I bought from Linders too, and it was quite clear the salesman had very little actual knowledge about the car/software. I mentioned about the UK speed sign recognition when picking up the car a month ago, and he said "no, don't think so, never heard of that", despite selling the car for 6months+. I might use that (along with Bluetooth unpairing) as a reason to ask them to upgrade to R46, depending on how that's working out for people. Not too many reports from people with that in here so far.
When you picked it up 3 weeks ago, R33 had been released for several weeks if not months at that point, so they should have already had it updated to R33. I collected mine 14th July and it had R33 on it, but maybe that was applied at the factory, rather than by Linders.