Over the last year I had 5 rentals with Europcar. All booked on flybmi.
Not one posted automatically although BMI was in the reservation and rental agreement.
The claims took from 7 to 56 days (a claim on Oct 11 to reply on Dec6) to get replied to, although they claim a reply is due in 30 days.
4 posted automatically between 7 to 14 days. They all appeared as 1500 miles. I didn't even bother to ask for a correction to 1700.
1 I had to request mannually after 30 days. 1700 miles posted as requested.

So I'd have to say the process is fundamentally broken.

GBM