There is every chance of a Telefonica "land-line".  The issue is this phrase.   You will never get copper wire to your finca if you're in the campo but you should expect Telefonica to supply you with an alternative - viz, what I call a radio phone ( because it isn't a cell phone but it has a SIM card) and works where there isn't a cell signal.   Dial 1004 from a mobile.  I haven't got all the options here to hand but you should be able to get to an English speaking desk and ask for a phone.  They'll say you are rediculous expecting them to install a radio phone when you do not have a street number or an address  but you say that as they can't supply a copper wire you demand an alternative.  It took us three years but we now have a 977 number in the campo.......we still buy Mundo cards from the Tobac ( 250 minutes of international calls for 6 euros!!) and we still use satellite for cruising the Internet.   Keep at it and you will win; they will try to tell you it is impossible but it isn't.  If you know a Spanish speaker then use them, bribe them, kidnap them.....you can get a phone.  good luck.