Buy a local SIM card to get internet service on your phone and use that along with a VoIP to instantly have a SIM phone plan! Cards are sold in different amounts of data and work like phone cards did in the 1990s: as you use the data by going online or making a call, the amount left is depleted until it's gone and you must buy a new card. Using this method along with a VoIP means you can make and receive calls as long as you have data left on your SIM.