When Vendors don't answer calls, emails, voicemails?

Although I was never involved in an online, or nation wide business, I did spend almost 50 years in a retail business. What I preached to my employees, I believe still applies.
Anytime you give your customer a reason to go to your competition, you give your competition an opportunity to take your customer.

There you have it.... I was the same way. However at the next level when you are doing everything you can and the customer still goes to the competition let it go. You more than likely don't need them in your life...... I had more than one and when we parted ways I never looked back.

JW