Teamviewer cancelation is really difficult

I used teamviewer remote about a year, however I no longer use it as much, so I request cancel it and called to Team Viewer Company on 25th July. However, the customer service guy said to me that they will still charge me and said that there is 28 days prior end of term policy to cancel. I don't know that. What is my solution for that? I really don't want to pay for another year which I no longer need the service. 

By the way, the customer support is really bad regarding cancelation. I tried to explain my company bought the license for 9pp, we just want to cancel 1 person, but they were so difficult and rules. They said that they sent me the reminder, but I didn’t receive any emails. I checked carefully, but I didn’t receive. I asked them why I didn’t receive the email. They didn’t respond. It make cancelation really difficult.