Contributions towards Local Authority care are calculated on household income and capital. It is not clear from the information you have put exactly what the income and the capital of the household is - it appears there are at least 2 people as both PIP and DLA are listed.
The Money Advice Service have some good information on this:-
If you have had a decision you are not happy with, I would suggest that you contact a Community Care specialist to go through the figures with you and discuss your options.
Hope this helps.
The Benefits Training Company