Cancel Shield Service Subscription - No Longer Needed

I would like to cancel my shield service for the following reasons:

1. When I subscribed, I was not aware that it required a one-year commitment. The subscription interface only indicated a monthly price of $3000.

2. Upon further investigation, I found that the shield service requires 1-2 months of learning to distinguish normal traffic, but my server typically does not stay active for such a prolonged period.

3. Due to the reason stated in point 2, I have not used the shield service anymore and it has remained idle for the past few weeks.

I apologize for my oversight in not thoroughly understanding the terms of use before subscribing to the service. However, I still hope you can assist me in canceling the service as it is of no use to me but requires monthly payments. Thank you.