I do not know what to do now

I tooked my dad that I was having really bad cramps and he got me a heating pad and my grandfather came downstairs and I thought that he was upstairs but he was not and he took it away from me and said that I was not allowed to have a heating pad and smashed my door in my bedroom door I'm ground for three weeks because I had a heating pad and my grandmother says that I smashed my door in my bedroom but I did not and I'm grounded because they are saying that I'm going to hurt myself by using a heating pad and they say that they love me and that is way they are not letting me use a heating pad and I'm thinking that they would let me have something for the pain so I do not know what to think right now and that means three weekends without my dad.