Utterly unacceptable and I think you should contact BMW UK.
From what I've gleaned on this forum over the past 18 months, it would appear that UK dealerships are a bit of a lottery and I'm very pleased to have the support of John Clark, Aberdeen.
Since buying my F10 last September, their service has been nothing short of exemplary. The car was in for a software update under warranty last week, which was estimated to take just a few hours, but they asked me if I'd like to have the new F12 (6 series convertible) for 24 hours whilst the work was being done - hmm tough decision there!
Of course they're trying to sell me the new car and from my time with it they're well on their way, but that's business and they do it very well.
I collected my car the next day and whilst I'd asked them not to wash it (standard procedure), they respected my wishes, but took it upon themselves to immaculately valet the interior.
As long as I have a BMW, John Clark will have my business.