British Airways bans another cello

BA is back to its bad old ways. Protest by the Singapore cellist Leslie Tan:

Dear British Airways,
I am a professional cellist who has been flying internationally with my cello, in a career that has spanned 40 years. And not once have I had any problems with flying with my cello, as I had always purchased a ticket for my cello.
Unfortunately I am now writing with regards to an arbitrary decision over an inane technicality that cost me at least an extra SGD 3000 and even resulted in me having to rearrange – over 4 long hours , and on my own – all my flights back home, with absolutely no help from anyone from British Airways, at the airport in A Coruña, Spain.
Here’s the timeline that led to such a stressful and displeasing experience:
I was in Spain to bring home to Singapore a cello I had sent there for repairs. I had bought an extra seat for my cello from A-coruna-Madrid- London, London-Singapore on British Airways. I was about to board when someone from the ground crew in Spain said my ticket for the cello was bought incorrectly and it contravened British Airways rules.
Let me explain – BA allows extra seats to be bought for musical instruments, but it has to be tagged under the passengers’ name.
I did just that for the London-Singapore sector; however, for the Spain-London sector the BA help desk said it was unable to help me with purchasing an extra seat so I had to purchase that sector via an online portal. (This usually requires me to buy the extra seat under different name. And I have done this without any problems ever).
On this trip I bought the extra seat with the name Tan/CelloExtraSeat.
Also, in good faith, since I had already made arrangements with BA for an extra seat for the London-Singapore sector, I made sure my A Coruña- Madrid-London were also BA flights (BA7105 operated by Iberia airlines. And BA459 operated by BA).
And just for clarity’s sake – I had 2 tickets. 1 for me and 1 for the cello. There was no double booking, no cheating on fares- I PAID FULL FARE.
At the A Coruña airport I was issued 2 boarding passes and was ready to head home.
However at the very last moment, at the boarding gate, I was told that there was no way I could get on, that BA would not let me get on, and that there was no other way they could help me rearrange that flight. They had apparently tried calling BA but no one was picking up.
So for the next 4 hours, in the departure hall, I had to try call BA in Spain, London and Singapore. No one from British Airways could help me resolve the issue. Eventually I had to REBOOK all my flights back to Singapore and I had to FORFEIT all my already booked flights as there was no way I was going to make the connections at Heathrow. And this included the extra seats I had already paid for!!!!
I stayed an additional night in Spain and I still don’t have my cello. The only reason for me to go to Spain was to hand carry the cello home, and now I will have to have it couriered back! And additionally, my partner was travelling with me, so she had to change her flights too!
In my 40 year career as a professional concert cellist, this is the first time I have been put through this nightmare. And not by a small unknown airline, but by an international airline with a rather prestigious standing!
I chose British Airways because I trusted you!