This particular phone has suffered a myriad of issues however if you’ve gotten two units with the same suppose a defect in a row one might think that that is a feature or more so just part of how the phone works. As far as a restocking fee goes if there is a problem with the device in the first 14 days there should be no restocking fee at a store. If you purchased online there should also not be a restocking fee. There is no restocking fee for a defective device within 14 days of purchase. That said some stores work differently than other stores but I would think that that would be a consistent rule across the board.
You might reach out to T-Mobile on Twitter or Facebook and let them take a look at the situation and perhaps you might get a credit to your account for the cost of that restocking fee. No promises but it is worth the effort.