Can this be changed?

I have a QRDO from my divorce. I was planning to start taking the pension at retirement age of 65. My husband since died. I’m the administrator on his estate. I called about his part of the pension. I was told that I was the survivor beneficiary. They sent me paperwork to start taking it, which I did. Now they are telling me that it was combined with the QRDO. I am appealing it, as that was not clear to me in the paperwork. Can you give me any advise?