Had a random help ticket opened recently (I don't recall escalating the issue!) which asked for more details about my flights. After providing that, I've been told my Cashback has been matched up and I should see it soon.

So does seem promising. The one I really care about (circa 20 pounds commission) will be the one to watch, and that should start moving into pending soon.

I also had a booking that I cancelled as well, so will be interesting to see how that works out.