Product: Checking or savings account

Hi, This complaint is in regards to my business checking account ending in XXXX with Fifth third bank under XXXX XXXX XXXX. This business account has been opened since XXXX. I have never had any issues until recently. Back on XX/XX/XXXX, i received an email stating my business bank account was overdrawn. I logged in and saw that it was overdrawn on two business accounts one XXXX XXXX and the other XXXX XXXX  XXXX. Immediately I logged in and i saw a negative balance for over $ XXXX for one account and $ XXXX for the other. I saw that next to it the account was marked fraud. I called my bank once they opened to get assistance in finding out what it was and what happened. I originally called the customer service line and they informed me I needed the disputes department. Disputes department said I needed business banking and then business banking said I needed the disputes team. So the transferring went on for a while until I finally stopped the next person who was foreign and asked them not to transfer me any longer. She said she was filing a dispute and I would hear from someone within XXXX business days. Long story short I called back no one called me when i gave the next person my disputes number they said that that case # didnt exist. So proceeded in giving me a new case number which I then submitted proof of the clients purchase order with her business partner. During this time they sent me copies of the checks in question. Next to the checks it was listed as altered fictious for checks dating back to XX/XX/XXXX. This really had me anxious because the checks were all pass 30 days old and nothing was flagged prior from my bank or the other persons bank. I proceeded to reach out to the client that wrote the checks and she blocked me on social media. My first thought was if your claiming fraud to your bank you should be interested in speaking to the business that the checks were written to. I sent my bank proof of purchase for the hair products. The client was working with a business partner in XXXX a logistics company called bandggroup. Which comes as no surprise the client in question traveled to XXXX for mission trips from what i could tell from social media. I even looked up her and her husband on XXXX  to confirm they existed. When these checks were deposited months ago i never sent product right away and I even asked the tellers to put holds on them to make sure they cleared. The disputes team handled the dipsutes and reversed the funds back to my account. Fast forward two weeks later the bank pulls another $ XXXX out of a completely different business account and freezes my funds and takes everything again~!! Not once have they even contacted me to tell me about these issues. I spoke to over 7 people at the bank and two local branches. No one seems to be able to tell me anything. One of the branches even mentioned they were marking fraud on my accounts! I am the victim and i'm being treated like the criminal. I would think bank protection would reach out to me by now with everything that was going on with my accounts. So now i'm petrified to bank with and have closed my accounts and insisting our non profit move funds to another institute as well. I just wish someone would help me with this situation because its causing problems for me to even run my business! I feel that the real criminals are getting away with this. I even asked my bank what is XXXX saying the client said about the checks i have no idea what altered fictious mean and i wasnt even contacted to show proof of what I had and what had been purchased. I have all purchase orders and shipping details if needed.