Declared volunteering, sent a permitted work form

Hi, I am on ESA since 2013 and PIP.

Recently I finished therapy and found sone volunteering with a NHS mental health project for 3 hours a week. I contacted a advice service to see whether I had to contact DWP and support me in telling them I was volunteering. The advice was yes I had to tell them and so I put a note in writing to my local jobcentre w a supporting letter from volunteer manager.

A month later, I received a PW1 permitted work form in the post w no covering note to explain why. I rang the number on the form and spoke to an ESA advisor who claimed that all volunteering is classed as 'work' and hss to ge approved via a permitted work form, even if it is unpaid.

I am now in a position to fill in a form that doesn't really capture what I am doing because it is unpaid and is just volunteering as hoc when I am well enough. I worry that not filling it in might see my benefits cut but that filling it in might imply I am doing 'work' or am ready to go from support group to work related work.

I asked the call handler to get the job centre person to ring me and explain why it is this form vs the old process of notifying them in writing. I have only ever filled out a PW1 once for permitted paid work. My note to the jobcentre laid out the role, hours, that occ health had assessed me plus my sig and my managers so I don't know what else they might want, I am not getting expenses.

Anyone had this happen? Anyone know if I can refuse to fill in the form bc it's not the right one? Bit worried that with Coffey wanting support group people in work, filling the form in is inviting trouble.