T-Mobile email contact for refund

I despise doing business on the phone. You can't half hear or understand each other because in most cases, you're talking to another country thousands of miles away and the rep speaks English as a second language. I also think account details over a phone is less secure.

I want an email addy for T-Mobile CS. They have mine, I should have theirs. I don't belong to any social media.

My wife and I rolled over from Ntelos to Sprint to T-Mobile. She had maximum service working from home. She paid the account waaaaay ahead. She died over a year ago. I now have rock bottom service with a flip phone. I might make one call per month, and receive 5-6 mostly junk. My bill averages $4 and change. The negative balance is enough to cover me for decades. I'm in my sixties. I need 3/4 of it refunded to my autopay account info. I need the money.

How do I go about getting that refund? Do I use one of the exec email addys I found online, or is there a more generic CS address I haven't found yet? I could create probable @t-mobile.com addys until I hit one that works. I have lots of time.