You are doing everything you can to be helpful, but your mother isn’t accepting the help. That suggests to me that her fear of the surgery is bigger than her pain. She complains about your father and grandmother because it takes the focus off the real issue — her fear. If I’m right, it’s very possible that she would only find something else to complain about if your dad started cleaning and grandma didn’t come so often.
My best suggestion for you is that you make an appointment to take her to see a surgeon who can explain to her how modern surgery can help her. Yes, she will be in pain after surgery for a short time. But with good physical therapy she will be out of pain and back into life within weeks. Perhaps if she has the facts from a doctor, she will be reassured enough to get the operation.
I wish you well.