What to write in the agreement on the use of the site to prohibit flooding and spam applications?

Question

Law in IT

There is a problem, the user on the site fills out the feedback form too many times. It means that he takes and makes 1000 applications, while he does not need anything from us, but he does it out of sabotage. We want to add a clause to the agreement on the use of the site stating that such behavior on the site is prohibited, and if the user does this, we can apply to the "authorities" to compensate for losses due to the time spent on processing applications.
What should we write in the site agreement to prohibit such behavior?

Answer 1

It's useless.
Effective ways to fight:
1. Complex captcha when sending an application
2. Possibility to send only for registered users

Answer 2

The idea is a little more than completely stupid, and by declaring such stupid ideas you show the general frivolity and unpreparedness of the project team.
Technically close this possibility, and when the user bypasses this restriction, then the right to apply for protection and restoration of their rights will arise.