I got a new job around a month ago, which comes with mandatory paid training for the first month. I don’t want to be too outing, but it’s care related, involving working with vulnerable adults.
I already have prior training and experience in this area, so I was feeling fairly confident about my abilities, but I have just been contacted by my manager that they cannot mark my training as completed as I haven’t demonstrated the necessary skills 
they referred to one day where I was shadowing a more senior staff member, who apparently has given really bad feedback about me, and told my manager that I have a cold/unkind attitude. I didn’t have this feedback from anyone else I’ve shadowed or worked with during the training, and I’ve never had that feedback at all in my career. It’s left me feeling quite deflated.
On a call to discuss this, i said I was happy to take the feedback on board and be more mindful of my attitude but that I was surprised to hear that feedback. My manager took that as me being ‘unable to reflect on my provision’
I genuinely have reflected on the day the bad feedback was referring to, and nothing notable happened at all. The staff member I was shadowing was quite unfriendly and seemed to want to pick holes in everything.
My manager has said I will need to redo another week of training so I can demonstrate more warmth, but I’m not sure if I want to proceed at all anymore, I feel like the feedback was quite unfair, didn’t have any real rationale (no examples of my unkind behaviour were given ) and it’s put me off the company quite a lot.
I feel a bit gutted as I want to do a nursing course and this experience would be really good for my CV, but I’m truly dreading another week where I know I will be scrutinised even more as they’ve marked me down as being uncaring 
I could financially afford to not take this job and keep looking, but the company is well known and respected.
Any words of wisdom welcome please! I’m feeling really torn and quite upset.