If you closed your account and T-Mobile won't refund money it owes you, here's what you need to do
In some circumstances, T-Mobile won't refund you money it owes you. Here's what you need to do,

If you've ported out of T-Mobile, or are planning on leaving the Un-carrier, try not to overpay before you cancel your account and leave T-Mobile for good. That's because the way T-Mobile handles an account that has been closed you might never get back the amount you overpaid the carrier. To add insult to injury, T-Mobile will continue to send you your statement each month showing you with a credit that you'd be entitled to receive but might never actually end up in your bank account.
For example, a Reddit subscriber with the user name gsmarquis mentioned that he left T-Mobile for an unnamed wireless provider with a plan priced at half the cost of his T-Mobile plan. After receiving a bill from T-Mobile for $75, which he paid, the Redditor received a bill showing that he had a credit of $47.69. Despite having overpaid T-Mobile and receiving invoices to prove it, the former T-Mobile customer was unable to get his money back.
The excuse made by the carrier was that the subscriber no longer had a T-Mobile account, which prevented the wireless provider from verifying an account that no longer exists. The former customer couldn't remember his PIN, and without that, once the account was cancelled, his identity couldn't be verified. No verification means no check could be cut by T-Mobile for the credit the carrier owed its former customer.
This happened to another T-Mobile customer who was owed a refund but had a cancelled account and he too could not remember his PIN. But this guy went to T-Mobile's elite customer service team, T-Force. We've seen many situations mentioned on social media where a T-Mobile customer could not get satisfaction from the carrier's traditional customer service and had to turn to T-Force to come out on top. In this case, T-Force was able to verify this customer's account and process the refund to the card it was made from.
Keeping in mind that you have T-Force as a backstop, if you are a subscriber, make sure you have your T-Mobile PIN memorized. Also, try not to close your account and leave T-Mobile before you are paid back for any overpayments you might have made. If you've closed your T-Mobile account with a balance in your favor and can't remember your account PIN, the carrier will probably not make you whole.
If you're in this situation, contact T-Force via X by sending a Direct Message (DM) to @TMobileHelp. Explain the complete situation in your DM and include your phone number.
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