Disgusting Service

I gave my car away and didn't need the service anymore but I was told to pay an amount way beyond what I would otherwise pay if I continued until the end of the contract. So I decided to leave it as it was. I paid for the service I don't need just to finish the term. I call a month early to give notice of cancellation at the end of the term but I'm told I have to do it 20 days before the end of the contract otherwise they cancel it effectively in 20 days. This translates to early cancellation which comes with penalties. Life happens, emergencies happen. I'm calling in early to avoid mishaps. I'm calling in not to cancel but give notice to cancel at the end of the term which is in a month's time but I'm force to agree to a cancellation within 20 days which has financial repercussions on my side. I'm extremely disgusted.