go to call center
The best way to call home is go to a call center ( centro llamadas in spanish)
You sit in little booths and just dial 1-area code and number. They have a little meter and it tells you in peso's how (cuanto questa) the call is.
I found this is the cheapist and best way. I think you have to go into Luperon to find one.
Just hop on a motochoncho (motorcycle taxi ) and tell him what you want.