I have an interesting one on the go at the moment - I stayed at the CP Dublin Airport a few weeks ago. Booked a standard breakfast flex rate through the PC website the day before.
When the points didn't appear automatically, I used the discrepancy form on the website to send it in (along with a stay in HI Munich City Centre which hadn't appeared either).
I got an email back stating that the HI Munich points had been added OK, but on examination of the CP Dublin stay they had:
found that this was booked through a third party.
Since when has priorityclub.com become a third party?!?
I've mailed them back and will keep at them.