You may be having a similar issue to me. I had my SIM card cloned. After that happened, they were able to disguise their phone to be my phone, according to the systems, and were pretending to be me. So much so, even Samsung itself can't tell the difference. I'm still fighting the battle. I would change a password.. They would already know it. This whole experience has been crazy but it's definitely taught me a lot about technology.
