ESA claim

Well as I am not suicidal, then do you think it still a good idea for me to send an extra letter explaining why I would find attending a job centre and doing certain tasks impossible. This would not be a substantial risk claim but a further explanation how my health conditions impact on my daily life. As I said before I have already sent the ESA50 form but I need the assessors to realise how limited I am

I rang the Centre of Health and Disability Assessment today to ensure they had received my ESA50 form. They said they got it on 21st and have returned it to DWP because it was late. I sent it special delivery, on the 18th. The letters said to return it by 18th. I tried returning it on 17th but (was late to post office cos of my health probs) and also really annoyingly there was a queue in the post office and by the time we got to the cashier she said the post man had been literally a minute before and it was too late to do special delivery for next day. Anyway I decided to write on the form sent special delivery 18th plus in the 'is your form late' box I ticked yes and no because I was not sure if 'send form back by 18th ' could mean put in post by 18th. So it was posted 18th for next day delivery of 19th. So I dont know why it is down as received 21st. Anyway Centre of Health and Disability Assessment advised me to ring benefit centre and ask for a DM call back, I did this but the benefits centre advisor refused to arrange a call back for me. She said the DM will decide whether to keep my claim /case open or not and there is nothing I can do. Can I do anything?

What should I say to the DWP ? They did not want to know earlier.