Product: Checking or savings account

On XX/XX/19 an unauthorized debit of {$2800.00} was taken from my Bank of America checking account as a debit card purchase from a merchant that I had previously done business with. There was a legitimate transaction with this merchant for {$360.00} that had posted 3 weeks prior. I immediately placed a call to the merchant. Several messages were left but never answered. That same day I called B of A and reported this transaction, still processing, as fraudulent. 
A fraud investigation was opened. I was told that even though the transaction was still processing, B of A could not stop it. The debit had put my account into overdraft. I was told that I would be given a temporary credit and that the overdraft protection and the associated fees would not kick in. I was assured that this would be thoroughly investigated and that the online banking message center would keep me posted on what what going on. 
The next day, the overdraft protection was triggered and a fee of {$78.00} was charged as well as daily interest on the cash advance. I didn't receive any messages in online banking. On XX/XX/19, I called to follow up and was told that it might take 2 weeks to resolve. I was reassured that I was 100 % protected from fraud and that I would receive a message from the investigator. I asked about getting the police involved and was told that it wasn't necessary. The person said that since the merchant used XXXX, when the money was put back in my account, XXXX would decide whether to involve the police in getting their money back from their client. 
On XX/XX/19 I received a letter dated XX/XX/19 that stated that the investigation showed that the transaction was authorized and that the claim was closed. 
Since I am the only one able to authorize a debit on my card and I did not authorize this transaction, I called to dispute this on XX/XX/19. I was told that since I had done business with this merchant previously, the case is legally considered a " billing dispute '' rather than the theft and fraud that it actually is. 
There is no possibility that this was an accident or misunderstanding! I have no contract with this merchant authorizing any kind of repeated payments or services. This merchant stole money from my checking account. If what the B of A rep said was true, then any restraurant or department store could simply use customers ' cards to charge again and again. If caught, there would be no penalty except possibly having to give the money back. 
I think that it is outrageous that B of A believes the merchant over their customer. I was not messaged about this or given an opportunity to prove that I didn't authorize this. The thief still has the money and I am racking up charges daily from the overdraft. 
I spent over 20 minutes on the phone today, thinking that this could be readily resolved. I explained the situation to 2 people, XXXX and XXXX ( a senior customer advocate ). They only offered to reopen the case, but with a 45 day window for resolution. They said they could look into a " hardship determination '' to see if I could get the money temporarily credited to my account. 
Part of my complaint is that B of A is benefitting financially from supporting theft and fraud by collecting the overdraft cash advance fees and ongoing daily interest. By calling it a " billing dispute '', my fraud protection doesn't apply and they continue to rack up fees.