Wrong forum, but my bank photocopies every check that goes through... I would be able to request a photocopy of any check that I cashed or deposited or wrote. In fact, my bank has that information available to me online and sends me sheets with the photocopies with my statement. If it were my bank, I'd know if it was a lie or not.
However, how did they know you cashed it at *YOUR* bank? I don't recall having to list the bank I do business with on any of the rebate forms. Listen to someone telling a lie.... they feel the need to make up extra details to make it more believeable.
There's a difference:
"our records show that the check was cashed" : could be the truth, or could be a lie...
"our records show that the check was cashed at your bank on Feb 21" : attention to details, but the details give it away as a lie because they couldn't have known what your bank is. The details are added in to make the story more believeable and that you have little recourse.
Now, if they mentioned the name of the bank, and it was your bank, that would make it more believeable.
But, if the check allegedly came in the mail, someone either stole the mail or opened mail not addressed to themselves... either way, felony. Request a copy of the cancelled check from the CSR as clearly it's needed as evidence for the police. Plus, get their name and tell them that someone from their company may be supoenaed to testify (especially if they lost or destroyed the evidence), perhaps even that CSR.
Then, tell them to double check their records to make sure the check was actually mailed. You don't want to go ahead with a criminal investigation if it's just the rebate center's mistake