My iPhone is being tampered

How do I stop current device tampering by someone else that I have not given permission to? Thanks in advance. Or are there classes provided to educate people on how to prevent someone doing this? Especially if someone may be an engineer or work for apple? Does anyone know who I can go speak with on an official capacity other than local law enforcement? Is there someone on the U.S. District level?

[Edited by Moderator]