Offer support over email and chat.
Every time I file a support request, I select my preferred contact as email. Nevertheless, I always get a phone call at an inconvenient time, and an email asking for a good time for a phone call to work on the ticket.
This is frustrating. Typically if my request isn't clear, it can best be cleared up with screenshots or copy/pasting IDs that can not be easily communicated over the phone.