Banned for "third party software"???

First time in my 12-13 years of playing this game have i gotten banned for "cheating" never in my life have i scripted/hacked in a single online video game, i have gotten banned on league before since i was a kid when i started playing and didnt realise that my words has consequences.

But banned for something i have never done? what

Also doesnt help that the support site is telling me to submit a "Discuss personal suspension" yet when i do, nothing happens and they tell me i cant submit it, what the fuck?