In the complaint procedure of the Department For Work And Pension (DWP) in the Internet in the following website
https://www.gov.uk/government/organisations/department-for-work-pensions/about/complaints-procedure
There is an online form to fill to make a complaint about Universal Credit (UC) but concerning Employment And Support Allowance (ESA) there is only a phone number to make a complaint.
I would like to know how to make a complaint in writing about Employment and Support Allowance (ESA)?