Anything to do with cars seems to be a minefield and one can hardly ever end up with a fair result however much 'right' is on one's side. In order to preserve one's sanity, one unfortunately has to 'call it a day' but as a parting shot one might have to write them a stinging letter showing one's utter disgust and contempt. But are they worth even this?
In my limited (
) experience of 40 years of car ownership, the three best car companies for help and support are Porsche, Mercedes and VW with BMW at a resounding bottom. The main problem with the latter are their awful, unhelpful, untrustworthy and arrogant dealers in the UK.