Lidl is definitely lid-l. Like the advert says, Lidl surprises and it's meant to sound like little
The British advert is just playing on the language ignorance of the British. I simply can't bring myself to pronounce it as Liddl. In German, it is Leedl.
However, I do pronounce Braun the English way but that's because I knew it as a brand before I learnt German.
And latte is not lartay. I think I dislike that more than anything.
As for L'occitane, I guess it depends if you pronounce it the French way or the Ocitan way (and if they are in fact different, my knowledge of French dialects isn't sophisticated enough to know).
I found this article which is quite interesting: www.sundaypost.com/inside-the-sunday-edition/how-do-you-pronounce-ikea-adidas-or-lidl-our-guide-to-getting-the-names-right/ I didn't even know that people pronounced Nutella anything other than Newtella or Nootella!