@hmworth:
The flight was intra-European, of course (LJU-FRA). So we're talking about 750 vs. 125 vs. 0 miles.
When I phoned the M&M service line the employee me that the request was still being processed, but it is hard to say how much that means given her incompetence (first tried to tell me that JP flights are not eligible for status miles, then didn't believe me I booked in U class and I think she never understood the nature of the problem).
So which way of contacting LH would you suggest to reach somebody who at least understands the problem and possibly has the means to resolve it (i.e., convert U to some class with equivalent mileage)?