Do you have small claims court in Switzerland? That might concentrate their minds. You might also try writing to "readers rants" in the travel section of the Sunday Times or to "Watchdog" at the BBC. You ay find houbara not the only one with this problem.
You should also write a detailed step by step outline of your complaint to the official agency in the UK for handling these complaints. They can at least force BA to address definitively their position, instead ofpassing you from pillar to post. You can find them here....
http://www.auc.org.uk/