Worst customer service experience ever

I too purchased from Samsung with corp discount.  I did purchase the unbranded version and paid outright, the corp deal saved me +$60 on the device itself outright before corp deal, then offered $300 for trade in vs $150, and I just moved my SIM from old device to new device - no activation needed.

I will say that I haven't had service from offshore, but that being said, they're all scripted and typically unable to help beyond a basic lookup and read from script.  US advanced tech team is typically quite good (as were Customer Care) .  The executive response team, however is typically quite rude, and will often say one thing, and put something else down in writing (they are who you deal with for FCC/BBB/PUC escalations).

Eg.  T-Mobile coverage shows 5G/4GLTE/Roaming (roaming on an address), T-Mobile execs claim that the area is 4G LTE only, having issues due to 'Sprint CDMA' in an area that never had Sprint service.  It is to be noted that there is only roaming service in the area for miles.  They send a letter with a contact number - who never answers (+3 months) or returns calls.