You won't get miles for the I class (award/upgrade) but you should get the miles for the originally booked PE class (N ?)
In the online form, did you ask for the miles of the I class or for the PE class? I think here might be the problem.
You can also fill in and print out the retroclaim sheet for "non star-alliance partners" and send it to Verl by snail mail or fax by adding a copy of your e-tix and the bording pass.