Doesn't surprise me, German companies always know better and will try to prove you wrong, whether you're their customer or supplier. Such is the business culture, I think.
Kudos for assisting your colleagues with better communication in English, I think this practice could be useful for many organizations with people that speak English as a foreign language.
My impression is that in Germany you bear the burden of proof that you actually have a problem, that its not your own fault, and that you did your part trying to fix it.
You usually can get good support in Germany ( even at government offices ) , IF you show up with your Leitordner ( legendary German ring binders) with all the receipts, all the possibly relevant account numbers, transaction ids and a detailed analysis of your own problem.
There is nothing that signals to German support staff that you have to be taken seriously like a ring binder, preferably with color coded markers at the margins and lots of punch pockets.
If you think this is satire, try it the next time you have an in person appointment...
The rest is entirely correct, though.
Yep. Its a plight that afflicts almost all engineers around the world, and German companies are even more afflicted by it due to the German engineering culture...