Why when I miss a call or try to call my Voicemail, are the calls being forwarded to one of my friends?

Ok so whenever someone calls me and I miss the call, or when I go to contacts and try calling my voicemail (which is set as *86) instead of going to my voicemail it forwards the call to my friend's phone and calls him. It's been happening for a few months now and it's anoying. Is it something I did? How do I change that? (We both have Verizon if it helps)Why when I miss a call or try to call my Voicemail, are the calls being forwarded to one of my friends?From your phone, dial *73- this will turn off call forwarding