Thanks everyone for your attention, I have now solved the problem.

As there appeared to be no way to find a geographic number for Air Europa in UK, I resorted to calling their office in the Netherlands which does have a normal landline number in Amsterdam, +31 207 956 095. Using a suitable calling service this is of course much cheaper than calling a UK 0870 number. The call diverted immediately to the same call centre in Palma de Majorca (I asked her) where calls via the UK 0871 number are diverted.

She traced my attempted booking through my card number, and told me they had some issues with the web booking process which caused the problem, and it would be confirmed in a day or two. But I had just happened to notice that the cost of the flight I was booking had meanwhile come down by about £120, so I asked if we could cancel the original booking, do it again at the lower fare, and refund the original payment. She took care of the whole rebooking and refund process, the call lasted 27 minutes so a big saving on call charges plus the lucky bonus of 120 quid off the flight cost . . . yippeeee!

I don't know if it would be appropriate to add the overseas alternative number to the database, I have used such a solution before and it can probably often be useful.

Anyway, again many thanks to everyone organising and participating in this marvellous website!

Cheers - Dick