banned for something i didn't do

a few days ago I got an email from riot saying I was banned for using 3rd party programs scripts or hacks and I do none of the above, I have spent well over $500 on this account and riot won't even tell me the game I got reported in even though I may have footage depending on what computer I was on. If someone from riot would at least comment on this or someone could contact riot for me that would be nice.