How Qatar Airways lost a customer:

I planned a third return CDG-DOH-BKK flying business class in a 12 month window to get enough miles for gold (was silver) when I got this mail from Qatar mentioning tier review would be no longer for 12 rollong periods but form Jan to Dec. Thus my next trip would fall outside obtaining gold.

I emailed them asking if they still would consider my case and I got an avoiding reply, in the style "Fly with us and we will see"

I switched to Etihad ever since, flying BKK-BRU and am gold for 5th year.
Sometimes I find Qatar to BRU 100 euro cheaper, but it is not worth the change since it still is the rule: (no rolling 12 periods fro consideration)
Qpoints are valid for one calendar year (January to December). You must earn a certain number of Qpoints each year to retain your membership status.

I always have 50kgs on the BRU-BKK direction (40 kgs flying bis + 15 gold status), I will loose gold status because I got a redemption business class ticket with EY next year but stay on track for getting my gold back until March 2016 flying business oct 2012, may 2013 and sept 2013.

A mail from Qatar confirming I would reach gold after my next planned trip would have kept me flying Qatar, and Qatar flies to BRU also at last, but you lost me