Long distance relationship


So I’m In a long-distance relationship with my boyfriend and he lives in London England and I live in Oregon USA and we have been together for nine months and he won’t call me on the phone and he never replies the longest I have waited for him to text me back was I believe a week and whenever I bring up the fact that I want to call him and that we need to talk because we’ve been together for so long it’s just weird that we haven’t called each other and it hurts me that he won’t call me and I know he is who he is because I had him send a picture of him holding up a sign that said my name and the date and he is 16 and I’m 13 I don’t know how to make him call me if you have any advice please help me I’m desperate to hear my boyfriends voice!!!! And I put a a picture him and a picture of me idk why