(Avoid app payments) I paid $482 for a closed account instead of the one that was open

I usually pay my service through the app and it usually goes smooth. This time I paid and still had no internet so I called. The person on the phone said I still had to pay so I asked why if I had just paid, we went back and forth, until she found out the payment went to an account that had been closed before. I asked her about a refund and she hanged up. The app used a closed account to charge me.