I have always been a lurker here just reading the forum, but unfortunately I now need specific help and advice.

I was booked to fly on BA0278 from SJC to LHR leaving about ten minutes ago, in first class, confirmed seat 2A.
I tried to check in online when it opened 24 hours ago, but was unable to, so (after checking this forum for the likely reasons) contacted youfirst by email for reassurance that I was definitely correctly booked on the flight and there was no problem with my seat assignment. I received reassurance that all was fine, so guessed from what I read here that I had probably been selected for SSSS enhanced security.

For this reason I went to the airport early, arriving about 3 and a half hours before the flight. When I went to the check in desk there was a long delay whilst the check in person called their supervisor who then came to inform me that I had been subject to involuntary denial of boarding and would not be on the flight. I was very upset to learn this as I am anxious about flying anyway partly due to having multiple disabilities and serious medical problems (which is why I had chosen to fly in first as the first Dreamliner seat is the most appropriate for my disability and medical needs). I was travelling with my husband who we had been able to check in online. He was sitting in economy (I know the contrast is very unfair by we can't afford two higher class tickets and as I said I have disability needs). Our bookings were linked so they were aware that we were flying together (I would never deliberately choose to fly alone as it is so difficult for me).

they offered for us to be rebooked on tonight's flight from San Francisco to London, but because of my disabilities it wouldn't be suitable to make this last minute change and we were not confident that we would have been able to get me to San Francisco in time to make the flight. The alternative was to offer to rebook me on BA0278 but on Wednesday (so a delay of four days) and this is what they did. My husband was completely unable to wait until then as he can't take the week off work. So we had to make the difficult decision of him going ahead with the flight as booked without me.

fortunately I was able to call a family member and arrange for somewhere for me to sleep tonight and that is where I now am, but essentially BA have just left me to fend for myself until Wednesday evening.

I am still very upset about these events, so I haven't had time to fully consider and research it yet, but I have just read EU regulation EC261 and it seems as though BA have totally disregarded it!

I wasn't informed of my rights after being involuntary denied boarding. I haven't been offered any compensation and I haven't been offered care (required under article 9). Article 11 also states that air carriers must give priority to carrying persons with reduced mobility. BA are aware this applies to me as I had wheelchair assistance booked and we made it very clear to the check in staff that being denied boarding would be particularly problematic for me due to my disabilities.

Thank you for reading this long message (and rambling because I am still upset). Can anyone offer any advice? What should I do now? And how do I make sure that BA pay me whatever compensation is due, and get me home safely whilst minimising the problems they have caused with this.

I have always chosen BA because I felt confident that I could rely on them and have always previously found them to be brilliant with regard to supporting passengers with disabilities. It has upset me so much to be essentially stranded alone and unsupported for four days and I still can't quite believe this is actually happening.