Measure everything and then experience will become a metric and focus on getting that metric up.

Create a consistent way to gather experience quality across your customer interaction methods (email, chat, phone ...) i.e.

How well did the * at * solve this *?
Extremely well
Very well
Moderately well
Slightly well
Not at all well

Gather and analyse ALL the metrics. Monitor trends and work tirelessly to improve these trends.

Get back to EACH customer with a Not at all well experience. Understand them. Discern the sources of frustration and counteract them setting clear EXPECTATIONS (critical).

Doing this relentlessly should put you on track.

Happy to follow this up.

Pere