Once you file a dispute through the credit card company, the dispute process is moved to the credit card company and now the company has a LOT less power on what might be happening. They also get severely impacted from having a high amount of charge back and hurts them the next time they want to negotiate their credit card rate.
So from a market perspective, it makes total sense for a company to ban you. You're causing them problems, refuse to follow procedure on how to handle the dispute, and hurt their bottom line in ways that could impact them at the rate of millions of dollar. They would rather not have you as a customer at all than deal with you again. Statistically, a customer that uses charge back is a lot likely to end up using it again, so they avoid themselves future trouble as well.