You could write them back and ask them why they sent two different copies of the same letter, removed the file, just like they asked, you say your router is secure (might as well check the logs to be safe), and they don't seem to be threatening any legal action (since the file was deleted), just canceling your account.

I'd say contact the company, and see what is going on would be your best bet.

Also, hello everyone. It's been awhile. :-)