Sounds like that is their policy and I suppose it stops just anybody from getting details. I have had another look for you but still can't find anything.
I would give the Historical Society in that area a go. See if they can shed any light on how you might go about getting your info. They may have old records in their collection.
If you are lucky there might be someone who is related to your people. Or there may be someone who is willing to help you and actually go to the cemetery for you. You should tell them you are unable to get there yourself.
I once went and took a photo of a house that happened to be just near me. It was a house that one of her distant relatives lived in who came out to Australia. I was able to look up an old 1947 directory that I have and confirm the name with her. I emailed it to the lady in Scotland and she was very grateful.
You just never know who is out there that would like to help you.