My dear as simple as the situation calls if that
sim-card registered in your name go to any Q-tel along with your ID or a copy of your RP and ask for cancellation that's it .... but u have to assure the sim-card is in your name since been bought 1st time from Q-Tel and if it's not u can also cancel it if this sim card is not in use any more after checking it @ Q-tel center ...go ahead and cancel it buddy.