Firstly, you might want to update the images so that they don't show your address.
Ideally, we should get a few things cleared up. You mention debt collection letter which you can safely ignore until you get a Letter of Claim from the courts - don't entertain these debt collectors, they're powerless to get anything from you. However, the main point is if its got to debt collector letters, usually that means that you have appealed and they have rejected your appeal or you haven't contacted them at all and your ability to appeal is now gone.
Can you claify if you've made an appeal or had any contact with group nexus?
