So a friend was able to receive and send international text messages on T-Mobile unlocked iPhone 5 without the $10 international texting plan she was told she would require. She's on one of those basic $30/month pay-as-you-go plan (non-contract). Will T-Mobile charge her for those international texts even if she's not bound by a contract and has paid for the plan in advanced, or will these international texts be drawn from her 1500 min. plan? She was told, per 1 text equals 1 min., but not sure how that would equate with international texts. This is her first month with T-Mobile. Thanks!