Vueling Airlines?
 

Trying to book a flight from Malaga to Bilbao, but for some reason they keep declining my card, eventhough it works perfectly elsewhere.

Also, all their phone numbers aren´t working???? With no reply to any emails??

Doesn´t inspire confidence.

My experience with Vueling was fine, I would not hesitate to use them again.

maybe there was a limit on how much you can use on your card at one time?