The whole 'not customer facing' barrier concept is in my view a symptom of a more general malaise in any organisation.

Of course there can be front-line customer service staff with a lower level of training, and the aim should be for the maximum number of queries to be resolved (correctly) by the cheapest staff, but it should be possible to escalate an issue all the way to the top if it is serious enough. And a properly managed and resourced organisation should ensure that is never necessary because the issue gets resolved at a lower level. Resolution can include telling the customer to get lost, of course.