PLEASE CANCEL MY ORDER AND STOP SENDING ME PAYMENT REQUESTS

I've been trying to cancel my order with them for a week now, on 4 different occasions. They will send you order cancellation confirmation emails but when you try to use a different ISP, they tell you, NO, YOU HAVE AN OPEN ORDER WITH SO AND SO. I mean, come on guys!! If we cancel your service, the least you can do is allow us the freedom to chose a different ISP. PLEASE!!!!!