It is no help to tell OP that the care home should do this, that or the other.
Perhaps they should; perhaps they can't, due to budget cuts and are at their wits ' end.
I don't know, OP doesn't, and frankly neither do all of you saying so.
I hope Katyj, you read the helpful answers and can ignore the other.
You find the care home unhelpful, which is what the staff there strikes me as being, so being demanding is probably not something you want to try. Could you manage a genuine fit of crying in front of the staff and not in your mother's room? Weep and wail about the state your poor mother is in , ashamed of being incontinent etc. etc.
It might work. Remember through your tears to tell the staff you know they are doing their best and are hamstrung by stupid regulations. I've tried this ploy with good results.