FURTHER UPDATE
I believe I was manipulated into paying CDER group. The enforcement agent told me that between the time TEC respond about my appeal and now, my car is still on an active search and will be towed if found. He suggested it was better to pay the fine of the latest CDER fine of £424 and then when TEC approve my case I can get a refund through Council.
In speaking to Council they do not take any liability now that I have paid.
They said they did not know what CDER group was talking about regarding this and this is not how it works.
I am now £424 out of pocket and trying to contact TEC on phone to see if CDER group can issue refunds or I can appeal it. Unlikely.