I had purchased Samsung S8 from T-Mobile. After paying off the amount device was unlocked and have been using with other carrier from last few months. I had to send the device back to Samsung to get it repaired. It came back with T-Mobile lock. I tried unlocking it using 'Device Unlock' app installed on the mobile but getting error message that 'Couldn't recognize the device, please contact customer care.'
Its been 5 days of multiple calling, talking to multiple associates, performing different steps suggested by all their associates/tech experts. However, no luck yet. I also tried with T-mobile as well as other carrier's SIM card to perform these steps. With other T-Mobile active SIM device works.
Samsung has confirmed that device has not been rooted and only T-Mobile can unlock it. Every time I speak to customer care and technical expert they request me to hang up to perform something and/or check something and they assure a call back. Till date, not a single executive has called back as promised.
I'm really frustrated and fed up and I think Legal Battle is the only option to get the issue resolved.