It's worth saying that you are not alone in having problems with BA. A Facebook group titled "British Airways Complaints Advice"has nearly 41,000 members - read from that what you will.

As a starting point, if BA or another company in a similar scenario is unfairly refusing to engage, Dixon suggests you can submit a data subject access request to retrieve recorded phone calls as evidence of what BA promised ... <snip> ... The main ADR schemes are Consumer Dispute Resolution Limited (AviationADR) and Centre for Effective Dispute Resolution (CEDR). BA subscribes to CEDR - so that's where you'd go. "I have found the ADR schemes to be very good with legitimate claims, and it's clear that many airlines deliberately flout the law because they know most people won't pursue it," said Dixon.