Hey there! So sorry that you're having a problem with your unlock request. Are you trying to unlock using the Device Unlock app, and it is telling you that the device is not eligible?
Have you reviewed the unlock conditions? You said that you bought $100 in the store, are you including the cost of the SIM in that? Activation costs are not included in the $100 refill requirement.
Also, is your SIM still active? Some folks have reported having issues unlocking with the app without an active T-Mobile SIM inserted, particularly when requesting a temporary unlock.
Did you try reaching out to 611 or chat to see if they can check the eligibility of the phone? You can also contact T-Force via Facebook or Twitter to check into it. Best of luck to you!
There's some awesome info in the post above. Please take a look at it and let us know if you need more help. Thanks.