ESA Mandatory Reconsideration Notice sent early

Thank you for your reply. The DWP failed to notify me of the decision made on 21/10/17 - Form LT54/ESA56 was not fully completed by the decision maker and I can see from looking at a copy of this Form that the decision maker failed to fully complete the Form and failed to complete the section "notify to customer on form/letter on ....." - this section was left completely blank. I am aware that this does not invalidate the 21/10/17 decision, but my understanding is that a decision is not fully effective until the date that it has been notified by DWP to the claimant? I only discovered the decision 'by accident' on 7/11/17 when I phoned DWP about a non-payment issue, and the call centre advisor informed me that I had been moved into the WRAG. I requested a call-back, which I received from DWP on 9/11/17, and the advisor informed me they could see that no notification of the decision made on 21/10/17 had been actioned nor sent to me. During the DWP call-back on 9/11/17 I requested a written notification of the decision to be sent to me, my decision letter is dated 9/11/17. My understanding is that a decision is not fully effective until it is acted upon and notified by DWP to the claimant - in my case this was on 9/11/17, so does that mean that I have until 9/2/17 before the DWP can request me to complete an ESA50? Thank you for your help.

Thank you for your reply. This feels like a never-ending nightmare which has been ongoing ever since notification of my re-assessment arrived in the post in January 2017. From your previous advice, my understanding is that retrospective evidence cannot be taken into account for appeal purposes, but in the ESA50 which I have recently been sent for completion, I can make it clear that my condition has deteriorated since the decision notified to me on 9/11/17?

If the worst case scenario does happen, would that mean I would have to go through the mandatory reconsideration process again, and possibly the appeal process all over again as well?