T-Mobile iPhone not unlocked, supplier won’t refund

I submitted this IMEI to a T-Mobile supplier and he won’t refund me now, even though he can’t unlock it.

He claims it’s not a T-Mobile IMEI.
I pulled GSX and it shows next tether as T-Mobile.

What do you guys think, should he refund or no?

Here is the GSX:

Model: IPHONE 6 MM 16GB GOLD
SerialNumber : FFMBL3L1G6MF
IMEI : 359******15206
FirstUnbrickDate : 12/31/15
LastUnbrickDate : 02/08/16
LastUnbrickOsVersion : 9.2.1
Initial Activation Policy : US GSM/VZW N61/N56 Service Policy
Next Tether Policy : US T-Mobile Locked Activation Policy
LastActivationPolicy : US T-Mobile Locked Activation Policy
Find My iPhone: OFF
Simlock : Locked