My ex was paying me £75 a week but kept controlling me with saying if I don’t do this and that he would stop it so I went to csa and he lied how much he earnt and was told to pay £37 a week which is an insult , I work full time and pay £900 a month for childcare , every time I receive it I send it back as I know he lied to pay as less he can , he sees my son 2 nights a week and has him every other weekend surely he should have to pay towards childcare need advice am I wrong to send it back is there anything I can do thank you