Not clear on what you’re disagreeing about. Staffers can write down the issues callers mention in their voicemails and straight telephone calls, yes?
In the past, I’ve taken the time to write and send letters, and I had a fairly good answer rate (one of Rubio’s, I have to mention, was fucken awful), but lately I’ve been calling and leaving messages instead (if I don’t get a human on the line).
At the base level, the method used to contact elected reps is less important than contacting them in whatever way is most comfortable to the person at hand. Make the call, write the letter, send the email, whatever, but make your voice heard.