Because the C&D looks 100% completely and totally fake. It does not fall in line or comply with any of their previous letters, and the followup response to it "yeah we called them, transferred departments, don't call them on your own and verify our story pls" is absolutely fishy.
If YOU didn't fake it, someone else did.
There is no way in fucking hell any of this is even remotely real. The C&D was fake, whether you faked it or not.