I was with wind also you need to call them and cancel your plan, if you can login your wind account it means that it's still active, I went to the wind store to do that but they told me to call customer service.
I had the same thing happened to me after activating my sim but after 1 hour it was fixed, it was because it took a while to transport the number. Did you have your sim active before transferring you number to public mobile?
