As the title says, apparently Online.Net has this line in their TOS that stated that if you want to cancel your service you have to cancel before 20th, else they will charge you for another month. I had a two server with them, cancelled one and kept the other but because I didn't cancelled early enough, I was charged for another month without able to use the server.
Don't really want to sounds like I am complaining all the time but this might be something people should know when they are cancelling dedicated servers. Most of the VPS providers will let you know off the hook even if you cancel on the last day, not for dedi providers I guess.