Yes, I don't really agree with some of the anti OP sentiment encountered further upthread. Not everybody is a mileage expert and those people are there to help you. Don't agree with being rude to the staff either, that gets you nowhere.
But in defense of the online mileage retroclaim facility, I have found it to be the most efficient of all FFPs. And in my case it seems to have always made mistakes in my favour, such as getting credited the miles for the class I was op-upped to!!