I think my LoL account got hacked

A few days ago, I installed Touch VPN from the official Google Chrome Web Store to try out the PBE and NA servers. Yesterday, after playing on NA, I accidentally left the VPN on. Today, while voice chatting with a friend in League, I heard a stranger's voice, and it seemed like they were listening to both my game screen and my conversation with my friend. I haven't watched anything like porn through the VPN. I got worried and deleted the VPN. The PBE server isn't illegal, and since the VPN was from the official Chrome store, it probably isn't illegal either, but... could I have been hacked?..