Product: Checking or savings account

Firstly I've been a Bank of America customer for 25 Years with both a personal and business account during this time. In light of our long established relationship, I opened a new business account in XX/XX/XXXX. 
Transactions have been fairly small, but steady while we build this business, and the account has never been overdrawn. I was able to secure an investor, a close friend of mine, and I deposited a check in the amount of $ XXXX on XX/XX/XXXX. I was informed at the time of the mobile deposit there would be a 'hold ', which I naturally expected. I received an email from B of A the same day confirming this hold with an availability of funds on XX/XX/XXXX. 
I received a further email on XX/XX/XXXX from B of A indicating the check was still on hold with a 'revised ' available funds date of XX/XX/XXXX at XXXX. I was totally fine with this. 
Today, XX/XX/XXXX, I attempted to check my online banking for this business account and I received an error message and I couldn't access my account. I immediately contacted the bank, initially the fraud department, who passed me along to business accounting, who told me the account was showing 'closed. ' She then passed me along to the department that handles this. After a short conversation with a lady who told me " the decision had been made and there was nothing I could do. '' I requested her supervisor, who asked me if she was been recorded, which I replied " No '', but she informed me I was, then proceeded to tell me many times it was " unfortunate '' but the decision could not be overturned. The bank " Felt the check was fraudulent ''. 
I asked her : Why they had made ZERO attempt to contact me in any way - " We don't do that ''. 
Why they had not contacted the issuing bank to check the validity of this check, which is a simple step for any bank - " We don't do that ''. 
I personally know the person who issued the check to me and his financial standing. This was something she had no interest in. 
I asked her why the bank did not allow the 7-10 days 'check clearing period ' to see the outcome? " The decision has been made '' Yet today XX/XX/XXXX the check 'cleared ' the issuing bank- XXXX XXXX with no issue after my friend went in to the branch to confirm this. The B of A representative told me to have my friend request a " notarized letter from his bank '' - XXXX XXXX  stating the " check is good ''. He asked his bank and they said " This is not something that is needed or given as the requesting bank can just call them to get the needed clearance '' B of A did not make any attempt to do this yet still had 6 more days before the 13th and their stated availability of funds! 
Why would I attempt to pass a fraudulent check after 25 years of a business relationship? I knew exactly where the check was coming from? The bank only needed to ask and leave the hold in place until the check cleared. 
This has caused me a huge amount of emotional hardship as well as time today. The B of A branch was less than helpful, and was quite rude " nothing I can do '' was his continual response. Also stating this may affect my other accounts with the bank!! 
This absurd policy has forced me to have to find an alternative bank and open a new business account. 
I have had to close down my online store. 
Any vendors who have standing debits will get bounced back. 
This has caused me a huge amount of strain, and inconvenience, all because of a decision based on the " Feeling '' a check 'may ' be fraudulent. Surely there should be a due process in reaching such a decision and an attempt to notify their customers before immeasurable damage is done to the business reputation and financial standing.