If you are good enough to be called a hacker constantly, you must be good at PvP. Take it as a compliment.
If you are seriously worried about getting banned - don't be. If you don't hack, there is no proof that could possibly be provided to a staff member. It's extremely unlikely you'd get falsely banned.
If these people who call you hacker are breaking any rules when doing so, such as using all caps and foul language, take some screenshots and report them...also, don't be afraid to tell them to get evidence and report you, 9 out of 10 times that will both make them shut up and they won't even bother recording you since they know you truly haven't shown any real hacks to them. Trust me, a lot of people know a hacker when they see them and are actually just raging when they died to you.
If they seriously won't stop at all, then ignore them to the best of your ability. Honestly, there is not much more that they can do other than attempt to report you and fail, or break some sort of rule like using all caps/foul language in an attempt to get your attention and annoy you...if you don't hack, they can do very little harm.