You have 3 option to get a hold of Visible customer service. On Visible home page bottom right hand part of the screen is a blue box, at first it will be a bot answering your question. Ask for a live agent. You will be put inline on chat and will take anywhere from 20 minutes to hour to countdown to one. Use a computer and not the app, the app will time out and if that happens you have to start over.
The other two options are Twitter messaging which I have not had any luck with, last time I tried it was 10 days and no response. Or Facebook messenger, for me was as fast as chat. Both of these the icons can be found in the bottom righthand corner of this page.