We had booked 2 rooms on the same floor, house keeping would slip a note under our door saying our 'do not disturb' sign was on and they didnt come in to clean. every morning the note was slipped into our doors at 8AM!!
One day we were back in the hotel resting at 430pm, house keeping knock on our doors and asked if we wanted our rooms cleaned. I told her the 'do not disturb' sign is ON, she then said: i just want to see if you want your room cleaned. I said the 'DO NOT DISTURB' sign IS ON so you shouldnt be ringing my door like this..
Obviously they are not trained properly.