Tried the SMS help system, which was an excellent service, but unfortunately resetting the voicemail PIN was not something that could be performed by them.
I was directed to the usual 789 number, which I tried, but gave up after some time after being in the expectedly long queue (the same occurred with the 0345 number as well).
As I've indicated in some of my previous postings, this issue has also occurred on a previous visit to Spain and a simple reset of the voicemail PIN allowed a new PIN to be set and access to the voicemail system was restored.
Please can a PM be sent to myself, the requisite security protocols be followed, and voicemail restore?
I'm sorry to see that you have not been able to access your voicemail in Spain due to the pin not being set. Generally we would advise to check here for the instructions of how to reset this pin, however, this only applies to being in the UK.
As you are now outside of the UK we would need to reset the pin for you, I will be happy to help you do this so I'll send you a PM to confirm your details.