IRS guidance on how to how to handle reporting on the death of an owner was published in 1987. When you are aware that the person has died you are on notice that the number is no longer valid and your are required to use the TIN of the new owner.
My advice is: If you know the SSN you are using belongs to a decedent and you cannot get the new owner's cooperation, remove the decedent's number from the account. Now, you have an account with no TIN and you must impose backup withholding. You will hear from the new owner shortly.
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.