3000 Rule,
As you can see, most posters here were "gentle" with you and most helpful and knowledgeable. Then there are the others who like to show everybody on here that their shoe size is far greater than their IQ and have no idea what goes on "behind the scenes" in the aviation world.
Piltdown Man hit the nail on the head. Most if not all airlines will not know their seats are broken (unless it is bleeding obvious to the cabin crew or picked up on an overnight/daily/weekly/monthly check) unless you the passenger informs the crew. They then should record the defect in the cabin logbook so that it can be repaired.
As far as your crew member saying that it is not a safety issue, total crap,you should NEVER have been allowed to occupy that seat. IT IS A SAFETY ISSUE and that crew member really should"nt be in the industry. And to think this person has to look after your safety in the event of an emergency.... give me strength!!!
As Skyjob has pointed out via the MEL book (and yes ruddman, it DOES get read with every defect recorded if said defect cannot be repaired in time for aircraft departure) you can use the seat, provided it is locked in the upright position. My company will move a customer to another seat (if available) and put a paxing crew/staff member in the broken seat. There are also other reasons where a seat cannot be occupied at all by anyone according to the MEL book. Hope this helps.