A channel operator (ChanOp or Op) is someone with a "@" by their nickname in a channel's names list. Channel operators are the 'rulers' of a particular channel. This means they can kick you out of their channel for any reason. If you don't like this, you complain to them or start your own channel and become a channel operator there yourself.
An IRC operator (IRCop) is someone who maintains a server or part of the IRC network. They cannot fix channel problems. They cannot kick someone out of a channel for you. They also cannot /kill (disconnect a user from their IRC server temporarily) someone just because you gave the offender channel operator privileges and said offender kicked *you* off. IRCops have better things to do than interfere in channel affairs.