Product: Checking or savings account

I wrote a check to XXXX XXXX  on XX/XX/XXXX from a XXXX XXXX checking account ( XXXXXXXX XXXX ) for $ XXXX and mailed the check using USPS mail drop. The envelope was stolen from the mailbox or post office, and the criminal ( apparently XXXX XXXX XXXX ) altered the payee name to her own name, and altered the amount to $ XXXX and then cashed the check ( copy in this file # XXXX ) at Bk of America in early XX/XX/XXXX. The check had been clearly altered and the lines that the payee name and dollar amounts had been whited out before writing in her new amounts. I was not called nor did Bank of America try to verify with me that this altered check was valid before they cashed it. The payment cleared in XX/XX/XXXX. 
My XXXX statement for XXXX came to me during the first few weeks in XX/XX/XXXX. I was on vacation when it came and by the time i returned home, looked at my statement, and noticed the discrepancy it was mid XXXX ( a reasonable timeframe ). I called XXXX immediately and they took the report, and said they would work on it and get back to me, but to expect approximately 180 days or longer. 
I placed many calls to XXXX and attempted to contact Bk of America as well to check on the status over the coming months. I went by XXXX XXXX XXXX branch offices to complete Fraudulent Item Activity forms and notarize them 3 different times. I notified the XXXX XXXX Sheriffs office and filed report. Bank of America told me over the phone that I could only deal with the initiating bank ( XXXX ) and they were my only point of contact on this claim. The XXXX Fraud officer was XXXX XXXX, and he was nearly imposible to talk to, and never once picked up a call ( attempted at least XXXX phone calls to him. He did call me back twice in over a year of calling. In mid XXXX ( XXXX ) I spoke to him he told me " I have good news and bad. The bad news is that Bk of America is denying the claim, but the good news is that XXXX disagrees with their findings and is going to reimburse you. I'll have confirmation next week and will let you know ''. I heard nothing more until XX/XX/XXXX, when he returned my call for the second time and said that nothing was resolved, and he denied telling me that XXXX was going to reiburse me. 
I have kept a log of my coorespondence, and it is fairly complete. Many more calls and meetings with the branch broker and manager followed, but XXXX XXXX has been unavailable, doesnt seem to care, not proactive, and I feel that XXXX has dropped the ball, and has caused huge delays in communicating with Bk of America . 
Bank of America has Officially denied the claim due to UCC rules that apparently require a reasonable time to notify the bank of discrepancies ( 30 days ). I notified them as soon as i say the statment and im sure XXXX has this noted in their records. It was shortly after the 30 days, but was done as soon as i was aware. But my complaint with the banks is that they were NEGLIGENT with cashing this altered check without calling me to verify it. It almost seems like an inside deal with the bank because how could any bank teller cash this altered check in good faith, knowing the circumstances ( XXXX XXXX  ( XXXX ), new bank account, altered check, {$50000.00} large check, etc. )! 
I am including a copy of the check, and other coorespondence that can help you review my case. 
Please review my case and information and I would appreciate you keeping me informed and if this can not be easily settled with the banks, then i'd like more information on what law firm or how best to file a legal lawsuit against them. 
Thank you very much for your assistance on this matter.