I have met some very rude LH FAs (even a purser who was super rude to me). I wrote a complaint to LH regarding a purser commented on me ordering too many drinks - I had 2 kids with me and we ordered a grand total of 5 drinks, which is less than 2 each. The purser said, 'are you having guests?' Then he used German talking to his colleague, '5 getrink'. I was shocked, so I said that we had to run to the boarding gate so we were thirsty'.
My kids paid full price of the ticket and most pax on board ordered 2 drink per person (it's a short haul flight so I don't expect that they will do 2 rounds drinks so I might as well get what I wanted).
So I got a reply from LH and they said the behaviour is not allowed and they will investigate the matter further. End of story.
If you don't mind using your time telling LH this, I think you should do so. The best is if you remember the name of the FA so they can at least know what is going on. I would suggest contacting LH in the US. Here in Europe the word service doesn't exist IMO.
I do understand that we are buying a cramp seat from A to B but I think fetching an aspirin doesn't take that long (I know they have a lot to do, but at least she should tell OP that he will have to wait until afterwards).