Sallie Mae overpay refund gone

I graduated with my degree in January 2022. I had a balance of unsubsidized student loans.

I then got a job, and had enough for a lump sum payment on the loans. This wiped it out so I never had to make any payments again. Fast forward to a few months ago.

My wife and I moved, while we were packing, we found a check from sallie Mae that was a refund check. I knew we paid them off from the online portal, so just assumed it was as spam and tossed it in a documents drawer.

Anyways, we found this like a day before moving. it was issued june 2022 with an expiration 180 days later, so either December 2022 or January 2023. We put it in a box to deal with when we got to our new location.

Of course, we lost the check. I have contacted Sallie Mae, they have records of an amount they returned.

I have my loan statements with the final statements saying the money was refunded

But they don’t have records of a check number and say that it’s out of their hands. They told me it most likely went to the unclaimed property of a state to claim. I have searched my state and every state associated with my college and sallie Mae and there is NOTHING.

Is there any hope of getting my money back