Appeal but no paperwork?

I applied for PIP and was refused
I appealed and it was going to Tribunal but I got a phone call offering me lower rate for both which I acccepted
In the letter it said I could make a new appeal if I wanted so I did to try and get higher rate
It was registered on the courts and tribunal service
I then got an email and letter saying Your appeal reference number: 1590596133145038
Dear Lewis Hunter
DWP has sent a ‘Response’ to your PIP benefit appeal. You should have received a copy in the post. The Response contains the information DWP used to make their decision on your entitlement to the PIP benefit.

However I have received nothing at all, and today I got another email reminding me to send further evidence if I want

Was I meant to get a new appeal pack? or do I rely on the old one from previously?
They have 2 different appeal numbers

Who do I complain to that I haven't received anything from DWP regarding the appeal?