Esa and non-cooperation?

It is clear that your mum needs to be placed in the support group - certainly the 'exceptional circumstances' criteria could be applied.

You are in a difficult position due to your mum's inability to co-operate.

In addition to previous advice, i would have thought you need to make contact with a GP, difficult i know due to patient confidentiality etc. Is your mum registered at the same practice as you? Could you talk about your mum's mental health and difficult situation regarding the benefit's issue with your own GP as a starting point and see what they suggest?

I would imagine you will need some kind of statement from a doctor as part of the reassessment process.

You would expect to be able to get some helpful advice from Jobcentre Plus/AtosHealthcare themselves???

I personally think there needs to be some kind of special procedures in place to deal with particularly difficult/complex cases.

Best wishes