I remember using an ad-supported phone calling service when visiting a cousin in Sweden. It sounds similar to this (ads that both people hear every few minutes) but it didn't use call-back.
Can any Swedes remember this service, or comment on whether it still exists?
"nearly four lakh FreeKalls have been made so far"?
A lakh or lac (/ˈlæk/ or /ˈlɑːk/; abbreviated L) is a unit in the South Asian numbering system equal to one hundred thousand [Wiki]