CSA not interested in my situation

i used to see my son every month as he lives 127 miles away, used to stay all weekend having fun also gave his mother money and bought things for my son, i have never seen my daughter the mother wont let me.

the csa got involved and are taking 97 pounds a week of me, this leaves me totally broke, ive rang them they said that was the figure due to some wages information they had got, i was of work for 6 weeks ill, now i have gone bac to work an they are taking 123 out of my wages every week. this is a nightmare as i cant pay my rent,gas ,elec, rates, visit my son or eat properly. i dont no what to do anymore the csa they not interested in my bills and survival, or even seeing my son. someone must have some ideas as what to do.