Question re legal guardianship in Wales. Do the guardians have to pay for the court case?

I’m trying to piece together my childhood. I live in Wales, and when I was 6, I was removed from my mother due to neglect as a result of her untreated schizophrenia. Social services were heavily involved. My grandparents took guardianship of me, with memories of going to a Manchester court for the case when I was 7 (1994). My grandparents said several times how expensive the process was.

My question is, if social services instigated my removal from my mother, how come the cost of the case wasn’t covered by them?