iPhone X SIM locked to a another country Carrier
(South Africa) Our company bought an iPhone X's in 2016 via amazon and it arrived carrier locked on T-Mobile. Calls have been made and emails sent to T-Mobile, which was not fruitful. We also tried 3rd party unlocking methods which also didn't work. A lot of money to try and get it unlocked but nothing is working. T-Mobile said the device never registered on their network, therefor cannot be unlocked.
Any ideas?