This has also happened to me, I'm really frustrated since I've had this account/spent money for 5 years now. I checked my match history, noted that there was an URF match as Viktor (who I don't play, and don't play URF) who went 16/2 and that definitely wasn't me, so I assume scripting. Is there something else I can point out to tell it wasn't me?
Sent in a ticket, to have support tell me 'we can't tell it wasnt you and there is no evidence of a compromised account' so the ban is still in effect. Most of the board posts I see people getting unbanned after their ticket.
I've asked support to check the IP the login came from, since I didn't even play any games yesterday. It seems a little unreal how often this keeps happening.