travel to Argentina with magenta plan

Just arrived in Argentina from the US.  I have a family Magenta plan.

Hoping someone can help me understand what type of coverage and rates I have in place.

When I landed in Buenos Aires I turned my phone on and it connected right away and I received and sent a text.  Then I turned of data roaming and went to airplane mode because I was unsure if I was going to get charged or not.

Anyone have experience with this scenario? 

thanks!