"Confusion over when my mother could go home"

My mother was admitted on the suggestion of her GP as she had only been out of hospital a few weeks from severe pneumonia and the symptpms had returned. When my mom arrived she waited 2 hours before seeing anyone, then told as she had no temperature nothing wrong (never had one 1st time round) then told she can have a bed for the night, ran a few tests overnight, we rang 1st thing in the morning told she will be released that day, Sister called to check up and clear some concerns, told to collect in 10 mins. Our mom had be placed in the "holding room" since 10.30am and it seems the person who took her there forgot where they had taken her as they were looking round as they wanted to take for MRI scan, when Sister arrived to collect our mom, the same person said what are you doing here, we are doing more tests and she won't be coming home yet, In my opinion this was an absolute shambles. How can they forget that they have told a frail woman who can hardly walk to stay in a room?