It seems simple. You have an angry customer on Twitter. They are ranting at you publicly. You reach out to them and get a conversation started. They go to DM you and, oops, they can’t. You know why? Because you haven’t followed them back. This is a major mistake. The customer is willing to take the conversation private, but you are impeding this and making the situation worse by not being accessible on a private channel. There’s a quick fix. Make a habit of following everyone who writes you with a comment, complaint, question. Anything. That way they can DM you privately.
Have a great day!