If you were having connectivity problems you never go and buy another device. You also put in a request to terminate service so what did you think was going to happen to the new device you purchased. There is a 14 day return policy minus a $35 restocking fee.
Now since Verizon let you out of a full contract you did not have to pay the $350 plus your plan amount lets say another $120. so $700.00 minus $350=$350-120.00=$230 so you are not out of $700
The problem being that device is as you said useless. But if it is brand new you can sell it to swappa or sell it to someone wanting Verizon service. You may even make more on the device and you will be happy.
Verizon already did you a good service, customer service or the store is now at the no way stage.
Have fun at your new provider, hope there is a cell signal there at your new home.