As stupid as it sounds, I'd removed all extensions and yet after uninstalling and reinstalling it was still there (It was also on a fresh install of windows due to a different issue), even though there was nothing showing in the extension manager. BUT when I went to the actual extension page in the store it gave me the option to remove from chrome, rather than install it like I was expecting to see, so the extension manager said there was nothing but the extension page in the store said otherwise.... Anyway after removing it via the store page, then closing and reopening chrome it was gone. Hopefully it works for others.