Product: Checking or savings account

Hello, I really hope you can help me and my business. 
Wells Fargo owes my company over {$500000.00}. Yes, {$500000.00} and they refuse to correct their mistake. 
It all started XX/XX/XXXX when I noticed a {$27000.00} ach that was taken out fraudulently. I called the bank immediately and I thought it was taken care of but it didn't get to the right department so I went in on the XXXX of XXXX and talked with a banker for quite some time. The banker did a stop payment on the merchant. I asked if there's anything else I could do to make sure this doesn't happen again and she said doing a stop payment on ANY transaction for {$27000.00} would definitely fix the problem. I left the bank feeling good about the solution. I double checked my Wells Fargo online account and did see the stop payment for the merchant and ANY transaction for {$27000.00}. All was okay. 
On XX/XX/XXXX I discovered several individual transactions for {$27000.00} on dates starting from the XXXX. I couldn't believe it and I know I didn't miss ANY of them because I check my bank account over 10 times a day. So somehow Wells Fargo had them flagged or hidden from me or they were stuck in pending and all showed up on the XXXX. I noticed this around XXXX XXXX and didn't know what to do because i couldn't make it to the bank before they closed so I called immediately and explained the situation and was transferred to the correct department. This was the most terrible phone call I have ever had. The woman told me she didn't see ANY transaction on my account for {$27000.00} and repeated herself over and over and started to get really upset with me. I don't know if it was the end of her shift or if she actually didn't see the transactions but that call was the worst experience i've ever had. Over {$200000.00} was taken out of my account and I had Wells Fargo pretty much tell me I was lying. I hung up with her because she couldn't do anything but repeat herself. I immediately called again. I was transferred to that same department and was told they were gone for the day. I tried calling at least 20 times to get a hold of someone that could help and no answer. It was a Friday so I had to wait the entire weekend to talk to that department. I own a small Business and sometimes a small amount like a couple thousand missing could really be devastating. I have over {$200000.00} gone. I called the bank as soon as they opened and went to a Wells Fargo branch at the same time. Over 10 hours on the phone or in person with a banker that day not one of the 30 people that I talked to could help me. Not one person said that I had a stop payment on ANY transaction for {$27000.00}. They did see the stop payment for the merchant but not a stop payment for ANY transaction for {$27000.00} The merchant changed there name but did the same amount of {$27000.00} each time. I was ready to give up. I lost employees because I couldn't pay them. I lost a large amount of business because I was either on the phone or in person at a branch. I spent over 100 hours that week trying to get somewhere. Then after all of that they explained that I didn't do a stop payment on that merchant and I waited to long to call or notify Wells Fargo in the Fraudulent transactions. They said that I notified them on that following Monday but that is definitely false. I 100 % called on Friday the XXXX right after the transactions showed up in my account. The one person that really threw me off told me if I click on the name of the merchant I would see its the same name as the previous stop payment. I couldn't believe it. I was told I notified Wells Fargo too late and it was a different merchant and those are the reasons they can't give me my money back and they closed the case. Both of those statements are inaccurate and I am aware that Wells Fargo records phone calls and can easily go back to hear me stating ALL of this. I was transferred to a different department once again and they reopened the case and then told me i waited too long to notify them. I'm easily out over {$500000.00} by now because of this and I will not stop until I reach a solution. I have almost 20 employees and they have been paid on XX/XX/XXXX like they were supposed to. I have lost employees because I couldn't pay them on time and have other upset employees that live paycheck to paycheck and this has really hurt them. They now have a bad taste for the business and I strive daily for that not to happen. 
There is so much more to this situation but this should get the point across