Synchrony Bank review: Furniture account with ashley furniture through synchrony bank.

I had a Furniture Account with Ashley Furniture funded by Syncrony Bank. I never paid late. Always on time. Then out of the blue the closed the account. They are now going in to my bank account taking money they are unauthorized to take! I have not spoken to these people in months and now they are trying to backdoor my bank account for an account they closed sending me a letter stating they closed saying I was a high risk? Wait what? Now my credit is tanked! What do I do now?