If you really weren't hacking then I know your pain.. I started playing csgo again randomly after just stopping for a few months. after about a week I got VAC banned with no hacks in use, I was too lazy to send a ticket and I really didn't give a shit i had another account with it so I got on the other account and played for one night only to be VAC banned again with a FN P90 Asiimov in my inventory the week that they came out.. $150 worth. VAC locked my inventory, I sent a ticket.
They told straight up that VAC doesn't make mistakes and that there is nothing they will do for me and to not use cheats. fucking arrogant pricks.
Oh and they wouldn't unlock my P90 either OR Give me evidence of me hacking.