Subscription I only want 1 year not 3 years

Why have you put me down for automatic billing I only signed up for 1 year. I’m only one person I do want or need 10 devices I only have a computer which I hardly use and an iPhone   There is no way I would have signed up if I knew what your going to charge after one year. If I can’t have this for 1 year then cancel my subscription 
tegard Rhonda Knott