I am eligible for Childcare Grant but have been denied

Hello to everyone,I have the following questions for help.Me and the wife are self- employed, but I am the only one working. We had a child and a few months after that I applied to study a full time degree in London North Hampton. 9 months and 2 weeks after the 2022-23 year has finished I applied to receive the extra support for the Adult Dependent Grant, Childcare Grant and Parents Learning Allowance. I have sent them a letter explaining why I am applying 3 weeks late(due to family reasons), I have attached the PFF2 form, attached my marriage certificate and my boy's birth certificate and the letter that we only receive the child benefit for the boy. My wife isn't working and we are not receiving universal credit or any other help. I received this letter now that says that we aren't entitiled to any support because we receive universal credit. Also it said that they have overpaid me £3000 and something and I have to give it back from the maintenance loan funding for next yeat ??!!I feel so sad and helpless for even asking for support and now even that will be withdrawn and I have to back pay. PS. We do not receive any other income.Is it possible for Student Finance to have made a mistake and written that we receive Universal Credit?From what I have read on the internet receiving the child benefit that is £96 a month isn't considered universal credit ?!Can someone please help with advise on what should I do with Student Finance England?