motobility car scheme?

I would be extremely grateful if someone can help me i am on the lower rate for mobility disability component my health has deteriorated so i tried to claim the higher rate but i was told i am not eligible because i am over the age of 65 which i found strange because the older you get the chances are more that your health will deteriorate and now i cannot claim a car on the motobility scheme which would be a great benefit to me so i could get out and about a bit more i really don’t know what to do can someone help.
Many thanks