With all the !!!!!!!!!!!!!! ? That was actually in the message?
From the spelling mistakes you received in that message, it can't be the officials.
Don't trust them imho unless you actually receive a real complaint.
"sellers like you stealing are hard work."
suppose to be
"sellers like you stealing our hard work"
"Stop this Know " >> "Stop this now"
"secretinternetpolice">> "Secret Internet Police"
Unprofessional writing, don't trust him/her.
If it was real, they would complain this issue to Amazon, and Amazon would remove it, instead of them contacting you directly.
Probably a competitor.