Petition Non dependent deductions

It is wrong that a carer of a disabled person, once that person reaches the age of 25 should have to pay £14.62 a week towards rent due to what is called non dependent deductions.
This is fine but as most disabled people -Like my son requires 24 hour care, how can they then have the non dependent deduction rule applied to their carers when they are totally dependent on us so therefore are not non dependents. If they lived independently it would cost the government and the tax payer a lot more than the £61 pounds they pay carers a week so why should carers be expected to pay it out of their money.