I booked a couple of flights on LH via the SEN hotline a while ago. For some reason the agent who made the booking spelled my first name incorrect on one of the bookings turning it into another popular first name (I guess he simply didn't pay attention while doing the second booking). As those tix were e-tix, I didn't notice until I got my BP from the Quick Check-in machine at the airport. In the SEN lounge I pointed the mistake out to the LH staff. They said "no problem" as your SEN number is correctly entered (and it indeed showed SEN on the BP even though the first name was incorrect).

Anyway, I entered those flights online for mileage credit and waited for 8 weeks. There is even a field online where you can enter the name in case it is different from your account (so I thought this must happen quite often). Today I received a letter telling me that they won't credit those flights because they are not in my name. Now, I know that is correct, however, my SEN number is printed on the BP and it clearly wasn't my fault.

Any ideas how to argue with LH to get them to credit the missing miles?