ESA very confused, please help.

This is from the DWP:

https://www.whatdotheyknow.com/request/403981/response/977193/attach/3/FOI%201855.pdf?cookie_passthrough=1

I suggest that you write a letter (template here: https://dpac.uk.net/2014/11/urgent-people-awaiting-wca-assessments-particularly-in-birmingham-please-read/)

Keep a copy and receipt of posting.

If your interview is soon then telephone then and say the same thing. Ask under what legislation this is mandatory and quote the DWP reply in the link I previously gave. It could be that you get another person who is not a numpty and knows what they are talking about. Ask to speak to a manager if you get the same response.

Make sure you get the person's name you speak to and time, date of call.

Those in the support group can attend work focussed interviews voluntarily if they wish to do so - for some people it is useful for others not.

It would help if you could tell us exactly what it says in the letter.