ALDI Store Assistant interview questions

Applied through Aldi website took almost 1 hour for Aldi in Bradwell Common Milton Keynes. Got a response 1 week later for and interview which was the next week. 1 week later I got an email to say I was successful and invited to a 2 hour work trial. There was suppose to be 2 of us the other person didnt turn up. The manager wasn't bothered so he made the assistant manager do the trial his name is Diamond. I was sat in the interview room and went through some paper works at that moment I asked Diamond if there are vaccancies and he said yes we are short staffed we need people some of us have to work extra to cover the shifts. They made me feel like I already got the job made me do so much as if they are paying me I had to do the delivery for them they were short staffed even made me sign some paperworks. DIAMOND went on his break and left me to manage by myself but if I need help to ask some girl she was working on delivery too the girl said also hope you get the job we are short staffed. After he finished his break which was for him time to go home Diamond came to get me and said the trial is over and I can go home he was like you did really good I will inform the Manager and you should be hearing from us within a few days I hope you get the Job. 1 week went I didn't get a response. I called the recruitment place to find out, the person said that I will get an email. 2 weeks later I received and email to say "You’ve done really well so far, however we do not currently have a vacancy that fully meets your requirements. All is not lost though. We will keep a record of your details for the next 12 months and if a potential vacancy comes up in that time, we will be straight back in touch. Thanks, The Aldi Recruitment Team" My question is I said I am fully flexible from 5am - 11pm every day. I can work on till and also on the shop floor. So what was this person talking about? Wasted of time.