I have personally seen a case (locally) where an inbound pilot had not got the PPR (required for 8-9am ops) and was refused landing. He had to orbit for maybe 30 mins.
He was mostly at fault for
- not having got notams (like ~50% of pilots, evident from not knowing the new ATIS)
- thinking that his VFR flight plan was "accepted"
- thinking that a flight plan would be OK for PPR
with the last two being used on the radio to try to get in. A bit sad really (not the pilot; it's the crap PPL training yet again).