Online checkin not working

I see someone else has had exactly the same problem. I am trying to confirm my seats, have waited until 24 hours before the flight, try to confirm and get a message saying that there have been too many attempts so the account will be locked for 24 hours. I am supposed to be in the air in 24 hours time. I phoned the international number and they were remarkably unhelpful. Very unsatisfactory customer service.