Colleagues maliciously find someone to tear up billboards and floor signs.

There is something wrong with your writing. People are also cram schools. Why do you write "cram schools please go to the third floor"? That is not equivalent to telling others not to go to the second floor.

when you advertise, you can write the name of your cram school and your floor. It's better not to write the word "go to the third floor", which is misleading. People's business is not good, so it will be angry to see you write like this again. It's best to talk to each other calmly, and it's more important to go out to do business with peace.

What building do you rent? Is there a unified company bulletin board on the ground floor? If this temporary billboard will be damaged by others, consider negotiating with the property to find a formal advertising bulletin board. If the other party destroys it again, it will be destroying the property.