Have not received my refund since it was received feb 29, 2024

The IRS is holding up my refund due to my husband's death.  He pasted away on 12-21-2023.  When I did my taxes since he was alive for the entire year I did not list him as passing away.  In March I mailed in his death certificate and told them I wanted my estimate tax to be filed under my social now.  The IRS received my email form on Feb 29, 2024 for tax year 2023.  In May I started checking online about why I had not received my refund.  Finally I called and was told that due to my husband's death a manual check was going to be sent to me in the next 4 to 6 weeks.  I called again in July and was told the office in Fresno had my paperwork and it was just a matter of time when a check would be cut.  Last week I called again and was told my return had finally been assigned to a person and that I would get a check in 4 to 6 weeks.  However they were really busy and it could take longer.  I asked if I could use the funds to cover this year's taxes and was told NO  If they don't return my refund by the end of the year, I will start to receive interest on my return.  There was no assurance when I would really see my refund.  Is this correct?  I am owed $2,246 and sure could use it.