I want to unsuscribe from Office Premium 365

I'm not an Office 365 user so I'm not sure how your question relates to an Apple iPhone user forum but the following from Microsoft Support may help: http://office.microsoft.com/en-us/help/cancel-your-office-365-home-premium-subsc ription-HA103984711.aspx

Why are you asking us? That's a Microsoft product/service. This is an Apple forum.