"Poor communication"

My mum was taken to hospital by ambulance following a GPs request from her place of residence (enhanced sheltered housing) She had become unwell and hadn't been eating and drinking...On arrival she went through A@E - The charge nurse there thought it would be better for her to go through the AAU which was more comfortable for my mum. We arrived early evening and she was promptly put in a bed in a cubicle. She had bloods done and then it was just a matter of waiting for the results. About 11:30pm I asked the nurse if the results had come back yet. She told me they had and three results were abnormal one suggesting she was dehydrated and would definitely be admitted and given fluids. She advised me I should go home as she hadn't seen a Doctor and wouldn't do for a few hours as they were busy...I left saying I would call and would be advised what ward she would have been admitted to. I called around 4am and was told my mum was still in the AAU settled and sleeping. I then called around 6am and was told she had been taken back to her place of residence by ambulance around 5am...     

 1. Why was I not informed of this? My mum is an adult with incapacity and I have POA. 

2.I was informed the next day through her GP surgery that all her blood results were normal!!! Who's blood results were given to me?

3.When I phoned up the AAU the next day to find out why this had happened I was told abruptly that they didn't know anything about it and couldn't discuss it with me! I can understand that but there is a way of speaking to people and directing them if they need more information.   

4. Is it normal practice to discharge a vulnerable patient with Parkinsons and lewy body dementia at that time in the morning!                                                     

This experience has left my mum who is very vulnerable feeling frightened to go back to the hospital  

Nurses