Product: Checking or savings account

On XX/XX/XXXX I wrote a check to XXXX for annual membership fee ( ck # XXXX for {$120.00} ) and  mailed in postbox. The check was cashed to the order of " XXXX XXXX '' in the amount of {$950.00} on XX/XX/XXXX and I discovered error when bank statement arrived XX/XX/XXXX. I took my checkbook register along with bank statement and copy of fraudulently cashed check which had arrived with statement in the morning of XX/XX/XXXX. XXXX XXXX at bank said this was second such event at the XXXX Branch of Rabobank in the past week. She said the crooks use utensils to grab mail from mailbox and chemically wash all but signature. She said she had closed my checking account ( # XXXX ) in order to limit risk on bank and me in case crooks had other checks of mine. " Declaration of Forged or Altered Check '' was filled out following multiple visits to bank including meeting with Senior Banking Services Representative XXXX XXXX and later Vice President Branch Manager XXXX XXXX who also consulted via phone regional Manager " XXXX ''. I originally told Rabobank had decided not to investigate since it took more money to research. XXXX also told me money would be restored to my account within 10 days. When money was not returned by XX/XX/XXXX I called XXXX XXXX ( XXXX was on vacation ). She called Rabobank central office and was told they had 90 days to return. A week later I received general mailing letter stating Rabobank was merging with Mechanics bank   effective XXXX. XXXX assured me as did representative at number on announcement letter that nothing would change. Money still not returned and it is now 90+ days since complaint. Call made to " concerns '' number. That representative went off phone call ( placed me on hold ) and then came back to say Mechanics bank would start the clock again AFTER the 90 days had expired and now would have another 120 days return money. After XX/XX/XXXX Rabo bank ceases to be a legal entity. I fear I will have no recourse since Mechanics bank may have no financial liability. What law is there in California that says a bank MUST return money when check has been fraudulently cashed? Also I called the Sheriff who deals with check fraud in our area ( XXXX XXXX ( XXXX ) XXXX on XX/XX/XXXX because I was concerned that XXXX at Rabobank said Rabo would not investigate. XXXX told me his hands are tied because banks do not generally cooperate ( i.e. they will not show him who cashed the check - later I learned Rabowould also not tell me at what vendor the check had been cashed. XXXX said it is suspected there are some liquor stores in XXXX XXXX, CA which cashed checks without I.D . but he is stimied by banks who will not share info. Therefore, no case was initiated. He did tell me bank must refund money to me. I feel I was defrauded by the crooks but the more significant defrauding came not at the hand of the crooks but rather at the hand of Rabobank who refused to return to me original check ( I have copy only ) and refused to tell me what vendor cashed the check. They must have this information. The fact they will no longer be a legal entity was known to them and I think these temporizing measures ( " we have 90 days before we have to return the money '' ) was intentional to avoid repayment at all. Shame on them!