child benefit

Hi, I need help, i have 2 children and an ex partner we shared our son 50/50 but our daughter resided mostly with me as she is older and can make her own choices. Anyway CB used to be paid to me for both children until Nov last year when the EX decided to make a claim for it, we had to fill out paperwork and wait for 6months for CH to come to the conclusion that I should get the CB for our daughter and the EX should get the CB for our son, sounds fair right? but its not as I have to rent a house to house myself and my children and I only have a part time job (due to stop myself from being made redundant) whereas the EX owns a 6 bedroom house, has a good job(25K) and a company car with company fuel, the house he lives in is paid for (with my help at the time) no morgage no loans just living costs. Now I am going to dispute the decision, but why are the CH not listening to me on this? surely they can see he has no money worries and is set up with a roof for life, where as I rent and I an currently in receipt of housing benefit but I think the decision made by CH reduces my housing benefit, I darent ring them as I will lose our rented house if i cannot paY rent!!!!!!!!!!!!!!!!!! what can I do about this???? PLEASE HELP ME

Unfortunately who is responsible for a child determines CB eligibility. There is no discretion for allowance to be made for the resources each parent has available to them under the CB rules.