Well, I've never heard of such a thing. Why do you need to install special software for online banking? I bank online, have for years now, and just use my web browser. This is how most people, at least here in the U.S., do their online banking.
You might visit this support page,
Need help?, and try the telephone support.
By the way, since you do not see KBC online banking in Add or Remove Programs or in CCleaner's uninstaller, how do you know you really have it installed? Is it on your Programs menu? Exactly what does it do that can not be accomplished with a web browser?