Are players allowed to make complaints regarding their ban or no??

or specifically if you believe its necessary are you technically allowed or able to sense the staff members were the ones who had banned you for vice versa and believe the ban in general was unfair including the response to the appeal (just questions I had in mind)
 
so I can make the complaint regarding both bans in the complaint and just gather all the evidence and stuff and go from there?
The complaint is only for the verdict. If it's regarding the ban itself, you would need to re-appeal the ban in the specified timeframe.