To add to Phil's post i had asked same question re error on website and recieved this reply today
Dear Michael,
Thank you always for your help. If you have a look our website, you will see the modifications. The Postcode is 30849, you can also use 30840 which is the one for Alhama town, but I had a mistake writting 30480.
Regarding the road, It will be ok Ctra Mazarron Km33(old situation)also Cta RM23 (new situation). Correos told me that it was not even necesary to mention because if you write Condado de Alhama is directly sent to the resort.
Regards,
Lali Gonzalez,
Resort Property Managemnt S.L.,