The letter is not bad and it is addressing issues that you wrote about in the original letter:
It starts out with giving you a biblical hope in your time of sorrow.
They are not saying that you lied, they are saying that there might be a misunderstanding.
They took a few months to answer you because they obviously wrote to the body of elders and they had to respond to their questions in writing. This was wise as it's always good to get both sides of a story.
They then point out what the elders did to help your father. This might have been overlooked as you are envolved emotionally. This of course is understandable. When a tragedy occurs, as imperfect humans, we tend to want to point fingers to find someone at fault.
Let me share an experience I had. One time a sister accused me of being negligent with my widowed mom. I was very furious at her! I take care of my mom, I pay her bills, I visit her daily, I run over to her home every single time she has a need. See, the sister accusing me did not see me doing all these things for my mom. Why did she accuse me of being negligent then? Because my mom had mentioned to her in service that she felt lonely. The sister immediately assumed that it's because I was negligent. But my mom was feeling that way because of having lost my father and the anniversary of this death was a few days away. So sometimes we are criticized even though we ARE doing things right. Could that have happend with the elders? Could they have been taking care of your father as the letter states, but it went unnoticed by you or your husband?
I wish you well.