IRA recovered from scammers, trying to redeposit

My father was the victim of scammers last year. They convinced him to liquidate his IRA to ‘invest’ with them. Luckily, the secret service was able to recover most of it.

I’m trying to utilize the self certification process through the IRS but the original financial institution is refusing to say they will accept and redeposit the funds. They won’t specify what their reasoning is for refusing.

Complicating matters, my father has since died so the account would be for his wife as the beneficiary.

Any guidance, insight or direction would be greatly appreciated.