Parent /Teacher Conflict: Is face to face better than, phone, email or letter?

This week's program was especially relevant to me. Until this year we have home schooled our daughter so I have very little experience with resolving issues with teachers. So last week when I found out that my daughter was being punished for missing an after school activity I went to visit the principal. I should note two things. One, I had sent a letter and called prior to the event to let the school know that my daughter would not be attending. Two, I'm very busy and really didn't have the time to leave work to visit the school. As it turned out, I talked with the principal, expressed my concern, heard his view and we arrived at a resolution ( I think). But the experience was uncomfortable as each of us was working so hard at demonstrating patience and sensitivity, that the whole experience was just plain awkward. I thought I was reasonable but it it felt like I was being the parent from hell. At work I do 90% of my business on the phone. Relationships are formed, deals are done and problems are resolved all without ever meeting face to face. Which do you feel is the best way to resolve parent / teacher issues, face to face, phone, email of letter?