A couple of weeks ago I was travelling back from Helsinki to Heathrow with BA. I had had a connecting flight from Oulu so was in the airport 4 hours before my departure. I arrived at the departure gate 20 minutes before my flight was due to leave, which was 10 minutes after the gate had opened, to be told that I was too late and that my bags had already been taken off the flight.
I found this very hard to believe not least because my airplane was an Airbus 321 with over 200 passengers and yet they had managed to find and extract my suitcase 10 minutes after the gate had opened.
They told me to go and find a BA desk for help. There isn't a BA desk in Helsinki airport but I did manage to find a FinnAir desk with staff willing to help. They gave me a telephone number in the UK which I phoned. At that stage my plane had or was about to depart so the friendly BA person in London told me that I was logged on their system as having missed my departure. Accordingly I would have to buy a new ticket which cost me �600.
I contacted BA customer service on my return by email. Eventually they responded saying that I need to ensure that I arrive at the airport on time. I explained again that I had been there for 4 hours, had checked in and had my boarding card. Again I questioned them claiming to have taken my case off the plane and closing the gate 20 minutes before departure.
The 2nd email ignored the points that I had made and told me that I need to ensure that I left sufficient time to get through security. They are completely ignoring the salient points and trotting out standard procedure jargon.
I feel let down and angry especially at having to pay �600 and having to stay in London overnight as I had missed my connection.
Any advice as to what I can do?

Hornem Welcome to FT

Airlines close the gate (aircraft door) before the scheduled take off time
Looks like you arrived late and they off loaded you, as normal airline practise
Your times do not make sense. To me all airlines take more than 10 minutes to board an A320.

BA closes the gate 20 minutes before the scheduled departure time so you need to be through the door by then unless boarding has been delayed. The time is printed in a large font on the BP. If you are lucky enough to find a sympathetic agent and have a good story then you might get put on a later flight but generally you just have to buy another ticket. "Customer Service" replies seldom seem to have any relevance to the complaint/request.

Welcome to FT, Hornem.

It's an unfortunate situation, but there's not much we can do because, on the salient matter of timing, your version of the story is different from BA's and we can't say which one is correct. When you checked in is not relevant, what is relevant is the requirement to be at the gate at least 20 minutes before departure time, when BA is scheduled to close the door and flight. If you are confident of your side of the story you should file a denied boarding claim under EC261 rules, but proof of this will be difficult.

Incidentally, there is a BA desk at HEL. It is located just to the right of the entrance, admittedly a little hidden from view. It would be to your back (and visible) as you queue for security screening.

U checked in 4 hours before the flight. I am wondering where were u and
what were u doing until 20 minutes before departure ?... why not be at the
gate 45 minutes prior just to be on the safe side ??