I totally agree. If the ban is based on the presence of an extension, then this is absolutely unacceptable. Many browser extensions are used to work.
By itself, the presence of an extension should not be proof of the player's guilt.
There is a concept: "Presumption of innocence".
It is not for me to prove to the inno administration that I am not guilty. They must provide proof of my guilt.
When asked to provide evidence, we do not receive anything!