请您保存好9月20日发送的邮件以及对方的回复。写一封正式的邮件给对方,询问为什么没有给您取消,并附上您之前的邮件记录,并要求对方的客户服务代表回电您,如果您没有接电话的话,请对方留言。
Keep a copy of the cancellation you mailed on Sep 20th, and resend it requesting confirmation that the service was cancelled. Ask them to have a customer service representative call you if they have any questions, and leave a message and phone number if you do not pick up.