Can I reactivate a bad ESN iPhone 6 Plus?

Hello,

As the title asks, I was wondering if my iPhone 6 Plus could be reactivated or replaced in any way. I knowingly bought the iPhone with a bad ESN just to use as an iPod, but upon further investigation the phone is factory unlocked for any carrier. I have also read that bad ESN's are a sign of lost/stolen property, but I followed up with T-Mobile (the carrier that locked it) and they reported that it is only due to outstanding balances on the account in which it was registered to; the phone was never stolen. This is where my situation seems a little unique because I see people who have bad ESN phones on accident and cannot confirm the cause.

I was wondering if there was any way to reactivate it or take it to Apple now knowing that it is not stolen property and still under warranty? I also wanted to see if I could pay off the balance to re-activate it, but T-Mobile would not allow that unless I had the account name. I currently am on Verizon and would like to use it on there if possible. It is eligible for that transfer as well barring the lock.

If not, I would still enjoy using it as an iPod, but I was surprised to find out it was factory unlocked and possible to use on Verizon if I can get the outstanding fees situated. Thank you!