I have been looking into VOIP and have found one or two better options than having to put up with all the s**t you get from Telepfonica. Have a look at -
http://www.voipreview.org/InternationalCallingRateSearch.aspx?source1=adwords&source2=inatl&gclid=CKzA1cTGy40CFQXalAodNBui6w  ( prices vary greatly so look at every page )
or http://www.voipbuster.com
reviews - http://lists.econsultant.com/top-10-pc-to-phone-voip-services.html
For 2Euro a month Skype offers about 3000 minutes per month with it’s Pro service ( yes it works in Spain. )
Please let me know of any services you use