"Dad sent home when still bad"

My dads doctor was on site at his house on Friday when ambulance got there and sad he needs to go to hospital as they think he has a kidney infection. My dad was taken into hospital by ambulance on Friday dinner time I was phoned and told he is just a bit confused but ok for returning home. I said after what I saw my self at dinner time I don't think he will be, I got 2 phone calls from hospital to say he will be going home on saturday tea time the ambulance dropped him off, his career was informed by you but at no time was the time given, the ambulance driver complained to a neighbour of my dad as no body on site. Carer calls 3 times till they found him. I was away for the day so I was unable to be there my dad went to bed Sunday night at 2000. As felt bad again I called his doctor to him again. They called on Monday to see him I have just been informed at 0800hrs on Wednesday morning by his carer they have phoned an ambulance again as he still bad. Why has my dad been messed about so much when anybody can see it's the same problem and nobody seems to care. Yes my dad has dementia but can and does normally enjoy going out to his clubs etc, and watching his football etc, but not at the min. His treatment by the hospital is not good enough needs to get better before you send him home.