Stolen iPhone in Bali: Passcode Change and Lockout

My mum lost her phone. The person who ‘found’ it returned it back to us. But when we received it we realised the passcode was different. we were locked out for 8 hours. When it finally was time, we put in her passcode and it locked us again for 8 hours. Since we are international (originally from AUS) we can’t access her phone to cancel her cards or do anything. We don’t know what to do and where to go in the meantime..

[Re-Titled by Moderator]